Easy CDDA Extractor 4.3.1 beta 1 serial key or number

http://xiph.org/vorbis/doc/Vorbis_I_spec.html

Contents

1. Introduction and Description

1.1. Overview

This document provides a high level description of the Vorbis codec’s construction. A bit-by-bit specification appears beginning in Section 4, “Codec Setup and Packet Decode”. The later sections assume a high-level understanding of the Vorbis decode process, which is provided here.

1.1.1. Application

Vorbis is a general purpose perceptual audio CODEC intended to allow maximum encoder flexibility, thus allowing it to scale competitively over an exceptionally wide range of bitrates. At the high quality/bitrate end of the scale (CD or DAT rate stereo, 16/24 bits) it is in the same league as MPEG-2 and MPC. Similarly, the 1.0 encoder can encode high-quality CD and DAT rate stereo at below 48kbps without resampling to a lower rate. Vorbis is also intended for lower and higher sample rates (from 8kHz telephony to 192kHz digital masters) and a range of channel representations (monaural, polyphonic, stereo, quadraphonic, 5.1, ambisonic, or up to 255 discrete channels).

1.1.2. Classification

Vorbis I is a forward-adaptive monolithic transform CODEC based on the Modified Discrete Cosine Transform. The codec is structured to allow addition of a hybrid wavelet filterbank in Vorbis II to offer better transient response and reproduction using a transform better suited to localized time events.

1.1.3. Assumptions

The Vorbis CODEC design assumes a complex, psychoacoustically-aware encoder and simple, low-complexity decoder. Vorbis decode is computationally simpler than mp3, although it does require more working memory as Vorbis has no static probability model; the vector codebooks used in the first stage of decoding from the bitstream are packed in their entirety into the Vorbis bitstream headers. In packed form, these codebooks occupy only a few kilobytes; the extent to which they are pre-decoded into a cache is the dominant factor in decoder memory usage.

Vorbis provides none of its own framing, synchronization or protection against errors; it is solely a method of accepting input audio, dividing it into individual frames and compressing these frames into raw, unformatted ’packets’. The decoder then accepts these raw packets in sequence, decodes them, synthesizes audio frames from them, and reassembles the frames into a facsimile of the original audio stream. Vorbis is a free-form variable bit rate (VBR) codec and packets have no minimum size, maximum size, or fixed/expected size. Packets are designed that they may be truncated (or padded) and remain decodable; this is not to be considered an error condition and is used extensively in bitrate management in peeling. Both the transport mechanism and decoder must allow that a packet may be any size, or end before or after packet decode expects.

Vorbis packets are thus intended to be used with a transport mechanism that provides free-form framing, sync, positioning and error correction in accordance with these design assumptions, such as Ogg (for file transport) or RTP (for network multicast). For purposes of a few examples in this document, we will assume that Vorbis is to be embedded in an Ogg stream specifically, although this is by no means a requirement or fundamental assumption in the Vorbis design.

The specification for embedding Vorbis into an Ogg transport stream is in Section A,“Embedding Vorbis into an Ogg stream”.

1.1.4. Codec Setup and Probability Model

Vorbis’ heritage is as a research CODEC and its current design reflects a desire to allow multiple decades of continuous encoder improvement before running out of room within the codec specification. For these reasons, configurable aspects of codec setup intentionally lean toward the extreme of forward adaptive.

The single most controversial design decision in Vorbis (and the most unusual for a Vorbis developer to keep in mind) is that the entire probability model of the codec, the Huffman and VQ codebooks, is packed into the bitstream header along with extensive CODEC setup parameters (often several hundred fields). This makes it impossible, as it would be with MPEG audio layers, to embed a simple frame type flag in each audio packet, or begin decode at any frame in the stream without having previously fetched the codec setup header.

Note: Vorbis can initiate decode at any arbitrary packet within a bitstream so long as the codec has been initialized/setup with the setup headers.

Thus, Vorbis headers are both required for decode to begin and relatively large as bitstream headers go. The header size is unbounded, although for streaming a rule-of-thumb of 4kB or less is recommended (and Xiph.Org’s Vorbis encoder follows this suggestion).

Our own design work indicates the primary liability of the required header is in mindshare; it is an unusual design and thus causes some amount of complaint among engineers as this runs against current design trends (and also points out limitations in some existing software/interface designs, such as Windows’ ACM codec framework). However, we find that it does not fundamentally limit Vorbis’ suitable application space.

1.1.5. Format Specification

The Vorbis format is well-defined by its decode specification; any encoder that produces packets that are correctly decoded by the reference Vorbis decoder described below may be considered a proper Vorbis encoder. A decoder must faithfully and completely implement the specification defined below (except where noted) to be considered a proper Vorbis decoder.

1.1.6. Hardware Profile

Although Vorbis decode is computationally simple, it may still run into specific limitations of an embedded design. For this reason, embedded designs are allowed to deviate in limited ways from the ‘full’ decode specification yet still be certified compliant. These optional omissions are labelled in the spec where relevant.

1.2. Decoder Configuration

Decoder setup consists of configuration of multiple, self-contained component abstractions that perform specific functions in the decode pipeline. Each different component instance of a specific type is semantically interchangeable; decoder configuration consists both of internal component configuration, as well as arrangement of specific instances into a decode pipeline. Componentry arrangement is roughly as follows:

1.2.1. Global Config

Global codec configuration consists of a few audio related fields (sample rate, channels), Vorbis version (always ’0’ in Vorbis I), bitrate hints, and the lists of component instances. All other configuration is in the context of specific components.

1.2.2. Mode

Each Vorbis frame is coded according to a master ’mode’. A bitstream may use one or many modes.

The mode mechanism is used to encode a frame according to one of multiple possible methods with the intention of choosing a method best suited to that frame. Different modes are, e.g. how frame size is changed from frame to frame. The mode number of a frame serves as a top level configuration switch for all other specific aspects of frame decode.

A ’mode’ configuration consists of a frame size setting, window type (always 0, the Vorbis window, in Vorbis I), transform type (always type 0, the MDCT, in Vorbis I) and a mapping number. The mapping number specifies which mapping configuration instance to use for low-level packet decode and synthesis.

1.2.3. Mapping

A mapping contains a channel coupling description and a list of ’submaps’ that bundle sets of channel vectors together for grouped encoding and decoding. These submaps are not references to external components; the submap list is internal and specific to a mapping.

A ’submap’ is a configuration/grouping that applies to a subset of floor and residue vectors within a mapping. The submap functions as a last layer of indirection such that specific special floor or residue settings can be applied not only to all the vectors in a given mode, but also specific vectors in a specific mode. Each submap specifies the proper floor and residue instance number to use for decoding that submap’s spectral floor and spectral residue vectors.

As an example:

Assume a Vorbis stream that contains six channels in the standard 5.1 format. The sixth channel, as is normal in 5.1, is bass only. Therefore it would be wasteful to encode a full-spectrum version of it as with the other channels. The submapping mechanism can be used to apply a full range floor and residue encoding to channels 0 through 4, and a bass-only representation to the bass channel, thus saving space. In this example, channels 0-4 belong to submap 0 (which indicates use of a full-range floor) and channel 5 belongs to submap 1, which uses a bass-only representation.

1.2.4. Floor

Vorbis encodes a spectral ’floor’ vector for each PCM channel. This vector is a low-resolution representation of the audio spectrum for the given channel in the current frame, generally used akin to a whitening filter. It is named a ’floor’ because the Xiph.Org reference encoder has historically used it as a unit-baseline for spectral resolution.

A floor encoding may be of two types. Floor 0 uses a packed LSP representation on a dB amplitude scale and Bark frequency scale. Floor 1 represents the curve as a piecewise linear interpolated representation on a dB amplitude scale and linear frequency scale. The two floors are semantically interchangeable in encoding/decoding. However, floor type 1 provides more stable inter-frame behavior, and so is the preferred choice in all coupled-stereo and high bitrate modes. Floor 1 is also considerably less expensive to decode than floor 0.

Floor 0 is not to be considered deprecated, but it is of limited modern use. No known Vorbis encoder past Xiph.Org’s own beta 4 makes use of floor 0.

The values coded/decoded by a floor are both compactly formatted and make use of entropy coding to save space. For this reason, a floor configuration generally refers to multiple codebooks in the codebook component list. Entropy coding is thus provided as an abstraction, and each floor instance may choose from any and all available codebooks when coding/decoding.

1.2.5. Residue

The spectral residue is the fine structure of the audio spectrum once the floor curve has been subtracted out. In simplest terms, it is coded in the bitstream using cascaded (multi-pass) vector quantization according to one of three specific packing/coding algorithms numbered 0 through 2. The packing algorithm details are configured by residue instance. As with the floor components, the final VQ/entropy encoding is provided by external codebook instances and each residue instance may choose from any and all available codebooks.

1.2.6. Codebooks

Codebooks are a self-contained abstraction that perform entropy decoding and, optionally, use the entropy-decoded integer value as an offset into an index of output value vectors, returning the indicated vector of values.

The entropy coding in a Vorbis I codebook is provided by a standard Huffman binary tree representation. This tree is tightly packed using one of several methods, depending on whether codeword lengths are ordered or unordered, or the tree is sparse.

The codebook vector index is similarly packed according to index characteristic. Most commonly, the vector index is encoded as a single list of values of possible values that are then permuted into a list of n-dimensional rows (lattice VQ).

1.3. High-level Decode Process

1.3.1. Decode Setup

Before decoding can begin, a decoder must initialize using the bitstream headers matching the stream to be decoded. Vorbis uses three header packets; all are required, in-order, by this specification. Once set up, decode may begin at any audio packet belonging to the Vorbis stream. In Vorbis I, all packets after the three initial headers are audio packets.

The header packets are, in order, the identification header, the comments header, and the setup header.

Identification HeaderThe identification header identifies the bitstream as Vorbis, Vorbis version, and the simple audio characteristics of the stream such as sample rate and number of channels.

Comment HeaderThe comment header includes user text comments (“tags”) and a vendor string for the application/library that produced the bitstream. The encoding and proper use of the comment header is described in Section 5, “comment field and header specification”.

Setup HeaderThe setup header includes extensive CODEC setup information as well as the complete VQ and Huffman codebooks needed for decode.

1.3.2. Decode Procedure

The decoding and synthesis procedure for all audio packets is fundamentally the same.

1.

decode packet type flag

2.

decode mode number

3.

decode window shape (long windows only)

4.

decode floor

5.

decode residue into residue vectors

6.

inverse channel coupling of residue vectors

7.

generate floor curve from decoded floor data

8.

compute dot product of floor and residue, producing audio spectrum vector

9.

inverse monolithic transform of audio spectrum vector, always an MDCT in Vorbis I

10.

overlap/add left-hand output of transform with right-hand output of previous frame

11.

store right hand-data from transform of current frame for future lapping

12.

if not first frame, return results of overlap/add as audio result of current frame

Note that clever rearrangement of the synthesis arithmetic is possible; as an example, one can take advantage of symmetries in the MDCT to store the right-hand transform data of a partial MDCT for a 50% inter-frame buffer space savings, and then complete the transform later before overlap/add with the next frame. This optimization produces entirely equivalent output and is naturally perfectly legal. The decoder must be entirely mathematically equivalent to the specification, it need not be a literal semantic implementation.

Packet type decodeVorbis I uses four packet types. The first three packet types mark each of the three Vorbis headers described above. The fourth packet type marks an audio packet. All other packet types are reserved; packets marked with a reserved type should be ignored.

Following the three header packets, all packets in a Vorbis I stream are audio. The first step of audio packet decode is to read and verify the packet type; a non-audio packet when audio isexpected indicates stream corruption or a non-compliant stream. The decoder must ignore thepacket and not attempt decoding it to audio.

Mode decodeVorbis allows an encoder to set up multiple, numbered packet ’modes’, as described earlier, all of which may be used in a given Vorbis stream. The mode is encoded as an integer used as a direct offset into the mode instance index.

Window shape decode (long windows only)Vorbis frames may be one of two PCM sample sizes specified during codec setup. In Vorbis I, legal frame sizes are powers of two from 64 to 8192 samples. Aside from coupling, Vorbis handles channels as independent vectors and these frame sizes are in samples per channel.

Vorbis uses an overlapping transform, namely the MDCT, to blend one frame into the next, avoiding most inter-frame block boundary artifacts. The MDCT output of one frame is windowed according to MDCT requirements, overlapped 50% with the output of the previous frame and added. The window shape assures seamless reconstruction.

This is easy to visualize in the case of equal sized-windows:

And slightly more complex in the case of overlapping unequal sized windows:

In the unequal-sized window case, the window shape of the long window must be modified for seamless lapping as above. It is possible to correctly infer window shape to be applied to the current window from knowing the sizes of the current, previous and next window. It is legal for a decoder to use this method. However, in the case of a long window (short windows require no modification), Vorbis also codes two flag bits to specify pre- and post- window shape. Although not strictly necessary for function, this minor redundancy allows a packet to be fully decoded to the point of lapping entirely independently of any other packet, allowing easier abstraction of decode layers as well as allowing a greater level of easy parallelism in encode and decode.

A description of valid window functions for use with an inverse MDCT can be found in [1]. Vorbis windows all use the slope function

floor decodeEach floor is encoded/decoded in channel order, however each floor belongs to a ’submap’ that specifies which floor configuration to use. All floors are decoded before residue decode begins.

residue decodeAlthough the number of residue vectors equals the number of channels, channel coupling may mean that the raw residue vectors extracted during decode do not map directly to specific channels. When channel coupling is in use, some vectors will correspond to coupled magnitude or angle. The coupling relationships are described in the codec setup and may differ from frame to frame, due to different mode numbers.

Vorbis codes residue vectors in groups by submap; the coding is done in submap order from submap 0 through n-1. This differs from floors which are coded using a configuration provided by submap number, but are coded individually in channel order.

inverse channel couplingA detailed discussion of stereo in the Vorbis codec can be found in the documentStereo Channel Coupling in the Vorbis CODEC. Vorbis is not limited to only stereocoupling, but the stereo document also gives a good overview of the generic coupling mechanism.

Vorbis coupling applies to pairs of residue vectors at a time; decoupling is done in-place a pair at a time in the order and using the vectors specified in the current mapping configuration. The decoupling operation is the same for all pairs, converting square polar representation (where one vector is magnitude and the second angle) back to Cartesian representation.

After decoupling, in order, each pair of vectors on the coupling list, the resulting residue vectors represent the fine spectral detail of each output channel.

generate floor curveThe decoder may choose to generate the floor curve at any appropriate time. It is reasonable to generate the output curve when the floor data is decoded from the raw packet, or it can be generated after inverse coupling and applied to the spectral residue directly, combining generation and the dot product into one step and eliminating some working space.

Both floor 0 and floor 1 generate a linear-range, linear-domain output vector to be multiplied (dot product) by the linear-range, linear-domain spectral residue.

compute floor/residue dot productThis step is straightforward; for each output channel, the decoder multiplies the floor curve and residue vectors element by element, producing the finished audio spectrum of each channel.

One point is worth mentioning about this dot product; a common mistake in a fixed point implementation might be to assume that a 32 bit fixed-point representation for floor and residue and direct multiplication of the vectors is sufficient for acceptable spectral depth in all cases because it happens to mostly work with the current Xiph.Org reference encoder.

However, floor vector values can span ∼140dB (∼24 bits unsigned), and the audio spectrum vector should represent a minimum of 120dB (∼21 bits with sign), even when output is to a 16 bit PCM device. For the residue vector to represent full scale if the floor is nailed to −140dB, it must be able to span 0 to +140dB. For the residue vector to reach full scale if the floor is nailed at 0dB, it must be able to represent −140dB to +0dB. Thus, in order to handle full range dynamics, a residue vector may span −140dB to +140dB entirely within spec. A 280dB range is approximately 48 bits with sign; thus the residue vector must be able to represent a 48 bit range and the dot product must be able to handle an effective 48 bit times 24 bit multiplication. This range may be achieved using large (64 bit or larger) integers, or implementing a movable binary point representation.

inverse monolithic transform (MDCT)The audio spectrum is converted back into time domain PCM audio via an inverse Modified Discrete Cosine Transform (MDCT). A detailed description of the MDCT is available in[1].

Note that the PCM produced directly from the MDCT is not yet finished audio; it must be lapped with surrounding frames using an appropriate window (such as the Vorbis window) before the MDCT can be considered orthogonal.

overlap/add dataWindowed MDCT output is overlapped and added with the right hand data of the previous window such that the 3/4 point of the previous window is aligned with the 1/4 point of the current window (as illustrated in the window overlap diagram). At this point, the audio data between the center of the previous frame and the center of the current frame is now finished and ready to be returned.

cache right hand dataThe decoder must cache the right hand portion of the current frame to be lapped with the left hand portion of the next frame.

return finished audio dataThe overlapped portion produced from overlapping the previous and current frame data is finished data to be returned by the decoder. This data spans from the center of the previous window to the center of the current window. In the case of same-sized windows, the amount of data to return is one-half block consisting of and only of the overlapped portions. When overlapping a short and long window, much of the returned range is not actually overlap. This does not damage transform orthogonality. Pay attention however to returning the correct data range; the amount of data to be returned is:

from the center of the previous window to the center of the current window.

Data is not returned from the first frame; it must be used to ’prime’ the decode engine. The encoder accounts for this priming when calculating PCM offsets; after the first frame, the proper PCM output offset is ’0’ (as no data has been returned yet).

2. Bitpacking Convention

2.1. Overview

The Vorbis codec uses relatively unstructured raw packets containing arbitrary-width binary integer fields. Logically, these packets are a bitstream in which bits are coded one-by-one by the encoder and then read one-by-one in the same monotonically increasing order by the decoder. Most current binary storage arrangements group bits into a native word size of eight bits (octets), sixteen bits, thirty-two bits or, less commonly other fixed word sizes. The Vorbis bitpacking convention specifies the correct mapping of the logical packet bitstream into an actual representation in fixed-width words.

2.1.1. octets, bytes and words

In most contemporary architectures, a ’byte’ is synonymous with an ’octet’, that is, eight bits. This has not always been the case; seven, ten, eleven and sixteen bit ’bytes’ have been used. For purposes of the bitpacking convention, a byte implies the native, smallest integer storage representation offered by a platform. On modern platforms, this is generally assumed to be eight bits (not necessarily because of the processor but because of the filesystem/memory architecture. Modern filesystems invariably offer bytes as the fundamental atom of storage). A ’word’ is an integer size that is a grouped multiple of this smallest size.

The most ubiquitous architectures today consider a ’byte’ to be an octet (eight bits) and a word to be a group of two, four or eight bytes (16, 32 or 64 bits). Note however that the Vorbis bitpacking convention is still well defined for any native byte size; Vorbis uses the native bit-width of a given storage system. This document assumes that a byte is one octet for purposes of example.

2.1.2. bit order

A byte has a well-defined ’least significant’ bit (LSb), which is the only bit set when the byte is storing the two’s complement integer value +1. A byte’s ’most significant’ bit (MSb) is at the opposite end of the byte. Bits in a byte are numbered from zero at the LSb to n (n = 7 in an octet) for the MSb.

2.1.3. byte order

Words are native groupings of multiple bytes. Several byte orderings are possible in a word; the common ones are 3-2-1-0 (’big endian’ or ’most significant byte first’ in which the highest-valued byte comes first), 0-1-2-3 (’little endian’ or ’least significant byte first’ in which the lowest value byte comes first) and less commonly 3-1-2-0 and 0-2-1-3 (’mixed endian’).

The Vorbis bitpacking convention specifies storage and bitstream manipulation at the byte, not word, level, thus host word ordering is of a concern only during optimization when writing high performance code that operates on a word of storage at a time rather than by byte. Logically, bytes are always coded and decoded in order from byte zero through byten.

2.1.4. coding bits into byte sequences

The Vorbis codec has need to code arbitrary bit-width integers, from zero to 32 bits wide, into packets. These integer fields are not aligned to the boundaries of the byte representation; the next field is written at the bit position at which the previous field ends.

The encoder logically packs integers by writing the LSb of a binary integer to the logical bitstream first, followed by next least significant bit, etc, until the requested number of bits have been coded. When packing the bits into bytes, the encoder begins by placing the LSb of the integer to be written into the least significant unused bit position of the destination byte, followed by the next-least significant bit of the source integer and so on up to the requested number of bits. When all bits of the destination byte have been filled, encoding continues by zeroing all bits of the next byte and writing the next bit into the bit position 0 of that byte. Decoding follows the same process as encoding, but by reading bits from the byte stream and reassembling them into integers.

2.1.5. signedness

The signedness of a specific number resulting from decode is to be interpreted by the decoder given decode context. That is, the three bit binary pattern ’b111’ can be taken to represent either ’seven’ as an unsigned integer, or ’-1’ as a signed, two’s complement integer. The encoder and decoder are responsible for knowing if fields are to be treated as signed or unsigned.

2.1.6. coding example

Code the 4 bit integer value ’12’ [b1100] into an empty bytestream. Bytestream result:

Continue by coding the 3 bit integer value ’-1’ [b111]:

Continue by coding the 7 bit integer value ’17’ [b0010001]:

Continue by coding the 13 bit integer value ’6969’ [b110 11001110 01]:

2.1.7. decoding example

Reading from the beginning of the bytestream encoded in the above example:

We read two, two-bit integer fields, resulting in the returned numbers ’b00’ and ’b11’. Two things are worth noting here:

• Although these four bits were originally written as a single four-bit integer, reading some other combination of bit-widths from the bitstream is well defined. There are no artificial alignment boundaries maintained in the bitstream.
• The second value is the two-bit-wide integer ’b11’. This value may be interpreted either as the unsigned value ’3’, or the signed value ’-1’. Signedness is dependent on decode context.

2.1.8. end-of-packet alignment

The typical use of bitpacking is to produce many independent byte-aligned packets which are embedded into a larger byte-aligned container structure, such as an Ogg transport bitstream. Externally, each bytestream (encoded bitstream) must begin and end on a byte boundary. Often, the encoded bitstream is not an integer number of bytes, and so there is unused (uncoded) space in the last byte of a packet.

Unused space in the last byte of a bytestream is always zeroed during the coding process. Thus, should this unused space be read, it will return binary zeroes.

Attempting to read past the end of an encoded packet results in an ’end-of-packet’ condition. End-of-packet is not to be considered an error; it is merely a state indicating that there is insufficient remaining data to fulfill the desired read size. Vorbis uses truncated packets as a normal mode of operation, and as such, decoders must handle reading past the end of a packet as a typical mode of operation. Any further read operations after an ’end-of-packet’ condition shall also return ’end-of-packet’.

2.1.9. reading zero bits

Reading a zero-bit-wide integer returns the value ’0’ and does not increment the stream cursor. Reading to the end of the packet (but not past, such that an ’end-of-packet’ condition has not triggered) and then reading a zero bit integer shall succeed, returning 0, and not trigger an end-of-packet condition. Reading a zero-bit-wide integer after a previous read sets ’end-of-packet’shall also fail with ’end-of-packet’.

3. Probability Model and Codebooks

3.1. Overview

Unlike practically every other mainstream audio codec, Vorbis has no statically configured probability model, instead packing all entropy decoding configuration, VQ and Huffman, into the bitstream itself in the third header, the codec setup header. This packed configuration consists of multiple ’codebooks’, each containing a specific Huffman-equivalent representation for decoding compressed codewords as well as an optional lookup table of output vector values to which a decoded Huffman value is applied as an offset, generating the final decoded output corresponding to a given compressed codeword.

3.1.1. Bitwise operation

The codebook mechanism is built on top of the vorbis bitpacker. Both the codebooks themselves and the codewords they decode are unrolled from a packet as a series of arbitrary-width values read from the stream according to Section 2, “Bitpacking Convention”.

3.2. Packed codebook format

For purposes of the examples below, we assume that the storage system’s native byte width is eight bits. This is not universally true; see Section 2, “Bitpacking Convention” for discussion relating to non-eight-bit bytes.

3.2.1. codebook decode

A codebook begins with a 24 bit sync pattern, 0x564342:

16 bit [codebook_dimensions] and 24 bit [codebook_entries] fields:

Clinical data
Pronunciation	kəʊˈkeɪn
Trade names	Neurocaine,[1] Goprelto,[2] Numbrino,[3] others
Other names	Benzoylmethylecgonine, coke, blow, crack (in freebase form)
AHFS/Drugs.com	Micromedex Detailed Consumer Information
License data
Pregnancy category
Dependence liability	High[5]
Addiction liability	High[6]
Routes of administration	Topical, by mouth, insufflation, intravenous
Drug class
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability
Metabolism	liverCYP3A4
Metabolites	Norcocaine, benzoylecgonine, cocaethylene
Onset of action	seconds to minutes[12]
Duration of action	5 to 90 minutes[12]
Excretion	Kidney
Identifiers
Methyl (1R,2R,3S,5S)-3-(benzoyloxy)-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylate
CAS Number
PubChemCID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
PDBligand
CompTox Dashboard(EPA)
ECHA InfoCard	100.000.030
Chemical and physical data
Formula	C17H21NO4
Molar mass	303.353 g·mol−1
3D model (JSmol)
Melting point	98 °C (208 °F)
Boiling point	187 °C (369 °F)
Solubility in water	≈1.8
CN1[C@H]2CC[C@@H]1[C@@H](C(OC)=O)[C@@H](OC(C3=CC=CC=C3)=O)C2
InChI=1S/C17H21NO4/c1-18-12-8-9-13(18)15(17(20)21-2)14(10-12)22-16(19)11-6-4-3-5-7-11/h3-7,12-15H,8-10H2,1-2H3/t12-,13+,14-,15+/m0/s1 Y Key:ZPUCINDJVBIVPJ-LJISPDSOSA-N Y
Data page
Cocaine (data page)
NY (what is this?)  (verify)

Cocaine, also known as coke, is a strong stimulant most frequently used as a recreational drug.^[13] It is commonly snorted, inhaled as smoke, or dissolved and injected into a vein.^[12] Mental effects may include an intense feeling of happiness, loss of contact with reality, or agitation.^[12] Physical symptoms may include a fast heart rate, sweating, and large pupils.^[12] High doses can result in very high blood pressure or body temperature.^[14] Effects begin within seconds to minutes of use and last between five and ninety minutes.^[12] Cocaine has a small number of accepted medical uses such as numbing and decreasing bleeding during nasal surgery.^[15]

Cocaine is addictive due to its effect on the reward pathway in the brain.^[13] After a short period of use, there is a high risk that dependence will occur.^[13] Its use also increases the risk of stroke, myocardial infarction, lung problems in those who smoke it, blood infections, and sudden cardiac death.^[13][16] Cocaine sold on the street is commonly mixed with local anesthetics, cornstarch, quinine, or sugar, which can result in additional toxicity.^[17] Following repeated doses a person may have decreased ability to feel pleasure and be very physically tired.^[13]

Cocaine acts by inhibiting the reuptake of serotonin, norepinephrine, and dopamine.^[13] This results in greater concentrations of these three neurotransmitters in the brain.^[13] It can easily cross the blood–brain barrier and may lead to the breakdown of the barrier.^[18][19] In 2013, 419 kilograms were produced legally.^[20] It is estimated that the illegal market for cocaine is 100 to US$500 billion each year.^[13] With further processing, crack cocaine can be produced from cocaine.^[13]

Cocaine is the second most frequently used illegal drug globally, after cannabis.^[21] Between 14 and 21 million people use the drug each year.^[13] Use is highest in North America followed by Europe and South America.^[13] Between one and three percent of people in the developed world have used cocaine at some point in their life.^[13] In 2013, cocaine use directly resulted in 4,300 deaths, up from 2,400 in 1990.^[22] It is named after the coca plant from which it is isolated.^[12] The plant's leaves have been used by Peruvians since ancient times.^[17] Cocaine was first isolated from the leaves in 1860.^[13] Since 1961, the international Single Convention on Narcotic Drugs has required countries to make recreational use of cocaine a crime.^[23]

Uses

Medical

Topical cocaine can be used as a local numbing agent to help with painful procedures in the mouth or nose.^[24]

Cocaine is now predominantly used for nasal and lacrimal duct surgery. The major disadvantages of this use are cocaine's potential for cardiovascular toxicity, glaucoma, and pupil dilation.^[24] Medicinal use of cocaine has decreased as other synthetic local anesthetics such as benzocaine, proparacaine, lidocaine, and tetracaine are now used more often.^[24] If vasoconstriction is desired for a procedure (as it reduces bleeding), the anesthetic is combined with a vasoconstrictor such as phenylephrine or epinephrine. Some otolaryngology (ENT) specialists occasionally use cocaine within the practice when performing procedures such as nasal cauterization. In this scenario dissolved cocaine is soaked into a ball of cotton wool, which is placed in the nostril for the 10–15 minutes immediately before the procedure, thus performing the dual role of both numbing the area to be cauterized, and vasoconstriction. Even when used this way, some of the used cocaine may be absorbed through oral or nasal mucosa and give systemic effects.^{[citation needed]} An alternative method of administration for ENT surgery is mixed with adrenaline and sodium bicarbonate, as Moffett's solution.^{[citation needed]}

Cocaine hydrochloride (Goprelto), an ester local anesthetic, was approved for medical use in the United States in December 2017, and is indicated for the introduction of local anesthesia of the mucous membranes for diagnostic procedures and surgeries on or through the nasal cavities of adults.^[25][2] Cocaine hydrochloride (Numbrino) was approved for medical use in the United States in January 2020.^[26][3]

The most common adverse reactions in people treated with Goprelto are headache and epistaxis.^[2] The most common adverse reactions in people treated with Numbrino are hypertension, tachycardia, and sinus tachycardia.^[3]

Recreational

Cocaine is a powerful nervous system stimulant.^[27] Its effects can last from 15 minutes to an hour. The duration of cocaine's effects depends on the amount taken and the route of administration.^[28] Cocaine can be in the form of fine white powder, bitter to the taste. When inhaled or injected, it causes a numbing effect. Crack cocaine is a smokeable form of cocaine made into small "rocks" by processing cocaine with sodium bicarbonate (baking soda) and water.^[12][29] Crack cocaine is referred to as "crack" because of the crackling sounds it makes when heated.^[12]

Cocaine use leads to increases in alertness, feelings of well-being and euphoria, increased energy and motor activity, and increased feelings of competence and sexuality.^[30]

Coca leaves

Coca leaves are typically mixed with an alkaline substance (such as lime) and chewed into a wad that is retained in the mouth between gum and cheek (much the same as chewing tobacco is chewed) and sucked of its juices. The juices are absorbed slowly by the mucous membrane of the inner cheek and by the gastrointestinal tract when swallowed. Alternatively, coca leaves can be infused in liquid and consumed like tea. Ingesting coca leaves generally is an inefficient means of administering cocaine.

Because cocaine is hydrolyzed and rendered inactive in the acidic stomach, it is not readily absorbed when ingested alone. Only when mixed with a highly alkaline substance (such as lime) can it be absorbed into the bloodstream through the stomach. The efficiency of absorption of orally administered cocaine is limited by two additional factors. First, the drug is partly catabolized by the liver. Second, capillaries in the mouth and esophagus constrict after contact with the drug, reducing the surface area over which the drug can be absorbed. Nevertheless, cocaine metabolites can be detected in the urine of subjects that have sipped even one cup of coca leaf infusion.

Orally administered cocaine takes approximately 30 minutes to enter the bloodstream. Typically, only a third of an oral dose is absorbed, although absorption has been shown to reach 60% in controlled settings. Given the slow rate of absorption, maximum physiological and psychotropic effects are attained approximately 60 minutes after cocaine is administered by ingestion. While the onset of these effects is slow, the effects are sustained for approximately 60 minutes after their peak is attained.

Contrary to popular belief, both ingestion and insufflation result in approximately the same proportion of the drug being absorbed: 30 to 60%. Compared to ingestion, the faster absorption of insufflated cocaine results in quicker attainment of maximum drug effects. Snorting cocaine produces maximum physiological effects within 40 minutes and maximum psychotropic effects within 20 minutes, however, a more realistic activation period is closer to 5 to 10 minutes. Physiological and psychotropic effects from nasally insufflated cocaine are sustained for approximately 40–60 minutes after the peak effects are attained.^[31]

Coca tea, an infusion of coca leaves, is also a traditional method of consumption. The tea has often been recommended for travelers in the Andes to prevent altitude sickness.^[32] However, its actual effectiveness has never been systematically studied.^[32]

In 1986 an article in the Journal of the American Medical Association revealed that U.S. health food stores were selling dried coca leaves to be prepared as an infusion as "Health Inca Tea."^[33] While the packaging claimed it had been "decocainized," no such process had actually taken place. The article stated that drinking two cups of the tea per day gave a mild stimulation, increased heart rate, and mood elevation, and the tea was essentially harmless. Despite this, the DEA seized several shipments in Hawaii, Chicago, Georgia, and several locations on the East Coast of the United States, and the product was removed from the shelves.^{[citation needed]}

Insufflation

Lines of cocaine prepared for insufflation

Nasal insufflation (known colloquially as "snorting", "sniffing", or "blowing") is a common method of ingestion of recreational powdered cocaine.^[34] The drug coats and is absorbed through the mucous membranes lining the nasal passages. Cocaine's desired euphoric effects are delayed when snorted through the nose by about five minutes. This occurs because cocaine's absorption is slowed by its constricting effect on the blood vessels of the nose.^[12] Insufflation of cocaine also leads to the longest duration of its effects (60–90 minutes).^[12] When insufflating cocaine, absorption through the nasal membranes is approximately 30–60%, with higher doses leading to increased absorption efficiency.^{[citation needed]} Any material not directly absorbed through the mucous membranes is collected in mucus and swallowed (this "drip" is considered pleasant by some and unpleasant by others).

In a study of cocaine users, the average time taken to reach peak subjective effects was 14.6 minutes.^[35] Any damage to the inside of the nose is because cocaine highly constricts blood vessels – and therefore blood and oxygen/nutrient flow – to that area. Nosebleeds after cocaine insufflation are due to irritation and damage of mucus membranes by foreign particles and adulterants and not the cocaine itself;^{[citation needed]} as a vasoconstrictor, cocaine acts to reduce bleeding.

Rolled up banknotes, hollowed-out pens, cut straws, pointed ends of keys, specialized spoons, long fingernails, and (clean) tampon applicators are often used to insufflate cocaine. Such devices are often called "tooters" by users. The cocaine typically is poured onto a flat, hard surface (such as a mirror, CD case or book) and divided into "bumps," "lines" or "rails," and then insufflated.^[36] The amount of cocaine in a line varies widely from person to person and occasion to occasion (the purity of the cocaine is also a factor), but one line is generally considered to be a single dose and is typically 35 mg (a "bump") to 100 mg (a "rail").^{[dubious – discuss]} As tolerance builds rapidly in the short-term (hours), many lines are often snorted to produce greater effects.^{[citation needed]} A 2001 study reported that the sharing of straws used to "snort" cocaine can spread blood diseases such as hepatitis C.^[37]

Injection

Drug injection by turning the drug into a solution provides the highest blood levels of drug in the shortest amount of time. Subjective effects not commonly shared with other methods of administration include a ringing in the ears moments after injection (usually when in excess of 120 milligrams) lasting two to 5 minutes including tinnitus and audio distortion. This is colloquially referred to as a "bell ringer". In a study of cocaine users, the average time taken to reach peak subjective effects was 3.1 minutes.^[35] The euphoria passes quickly. Aside from the toxic effects of cocaine, there is also danger of circulatory emboli from the insoluble substances that may be used to cut the drug. As with all injected illicit substances, there is a risk of the user contracting blood-borne infections if sterile injecting equipment is not available or used. Additionally, because cocaine is a vasoconstrictor, and usage often entails multiple injections within several hours or less, subsequent injections are progressively more difficult to administer, which in turn may lead to more injection attempts and more consequences from improperly performed injection.^{[citation needed]}

An injected mixture of cocaine and heroin, known as "speedball" is a particularly dangerous combination, as the converse effects of the drugs actually complement each other, but may also mask the symptoms of an overdose. It has been responsible for numerous deaths, including celebrities such as comedians/actors John Belushi and Chris Farley, Mitch Hedberg, River Phoenix, grunge singer Layne Staley and actor Philip Seymour Hoffman. Experimentally, cocaine injections can be delivered to animals such as fruit flies to study the mechanisms of cocaine addiction.^[38]

Inhalation

Inhalation by smoking cocaine is one of the several ways the drug is consumed. The onset of cocaine's desired euphoric effects is fastest with inhaling cocaine and begins after 3–5 seconds.^[12] In contrast, inhalation of cocaine leads to the shortest duration of its effects (5–15 minutes).^[12] The two main ways cocaine is smoked are freebasing and by using cocaine which has been converted to smokable "crack cocaine". Cocaine is smoked by inhaling the vapor produced when solid cocaine is heated to the point that it sublimates.^[39] In a 2000 Brookhaven National Laboratory medical department study, based on self reports of 32 abusers who participated in the study,"peak high" was found at mean of 1.4min +/- 0.5 minutes.^[35]Pyrolysis products of cocaine that occur only when heated/smoked have been shown to change the effect profile, i.e. anhydroecgonine methyl ester when co-administered with cocaine increases the dopamine in CPu and NAc brain regions, and has M₁- and M₃- receptor affinity.^[40]

Smoking freebase or crack cocaine is most often accomplished using a pipe made from a small glass tube, often taken from "love roses", small glass tubes with a paper rose that are promoted as romantic gifts.^[41] These are sometimes called "stems", "horns", "blasters" and "straight shooters". A small piece of clean heavy copper or occasionally stainless steel scouring pad – often called a "brillo" (actual Brillo Pads contain soap, and are not used) or "chore" (named for Chore Boy brand copper scouring pads) – serves as a reduction base and flow modulator in which the "rock" can be melted and boiled to vapor. Crack smokers also sometimes smoke through a soda can with small holes on the side or bottom.^{[citation needed]} Crack is smoked by placing it at the end of the pipe; a flame held close to it produces vapor, which is then inhaled by the smoker. The effects, felt almost immediately after smoking, are very intense and do not last long – usually 2 to 10 minutes.^[42] When smoked, cocaine is sometimes combined with other drugs, such as cannabis, often rolled into a joint or blunt. Powdered cocaine is also sometimes smoked, though heat destroys much of the chemical; smokers often sprinkle it on cannabis.^{[citation needed]} The language referring to paraphernalia and practices of smoking cocaine vary, as do the packaging methods in the street level sale.^{[citation needed]}

Suppository

Another way users consume cocaine is by making it into a suppository which they then insert into the anus or vagina. The drug is then absorbed by the membranes of these body parts. Little research has been focused on the suppository (anal or vaginal insertion) method of administration, also known as "plugging". This method of administration is commonly administered using an oral syringe. Cocaine can be dissolved in water and withdrawn into an oral syringe which may then be lubricated and inserted into the anus or vagina before the plunger is pushed. Anecdotal evidence of its effects is infrequently discussed, possibly due to social taboos in many cultures. The rectum and the vaginal canal is where the majority of the drug would be taken up through the membranes lining its walls.^{[citation needed]}

Adverse effects

A 2010 study ranking various illegal and legal drugs based on statements by drug-harm experts. Crack cocaine and cocaine was found to be the third and fifth overall most dangerous drugs respectively.^[43]

Acute

With excessive or prolonged use, the drug can cause itching, fast heart rate, hallucinations, and paranoid delusions or sensations of insects crawling on the skin.^[44] Overdoses may cause abnormally high body temperature and a marked elevation of blood pressure, which can be life-threatening,^[44]abnormal heart rhythms,^[45] and death.^[45]

Anxiety, paranoia, and restlessness can also occur, especially during the comedown. With excessive dosage, tremors, convulsions and increased body temperature are observed.^[27] Severe cardiac adverse events, particularly sudden cardiac death, become a serious risk at high doses due to cocaine's blocking effect on cardiac sodium channels.^[45]

• 

  Opioid involvement in cocaine overdose deaths. Green line is cocaine and any opioid (top line in 2017). Gray line is cocaine without any opioids (bottom line in 2017). Yellow line is cocaine and other synthetic opioids (middle line in 2017).^[46]

• 

  Delphic analysis regarding 20 popular recreational drugs based on expert opinion. Cocaine was ranked the 2nd in dependence and physical harm and 3rd in social harm.^[47]

Chronic

Side effects of chronic cocaine use

Chronic cocaine intake causes strong imbalances of transmitter levels in order to compensate extremes. Thus, receptors disappear from the cell surface or reappear on it, resulting more or less in an "off" or "working mode" respectively, or they change their susceptibility for binding partners (ligands) – mechanisms called downregulation and upregulation. However, studies suggest cocaine abusers do not show normal age-related loss of striataldopamine transporter (DAT) sites, suggesting cocaine has neuroprotective properties for dopamine neurons.^[48] Possible side effects include insatiable hunger, aches, insomnia/oversleeping, lethargy, and persistent runny nose. Depression with suicidal ideation may develop in very heavy users. Finally, a loss of vesicular monoamine transporters, neurofilament proteins, and other morphological changes appear to indicate a long term damage of dopamine neurons. All these effects contribute a rise in tolerance thus requiring a larger dosage to achieve the same effect.^[49] The lack of normal amounts of serotonin and dopamine in the brain is the cause of the dysphoria and depression felt after the initial high. Physical withdrawal is not dangerous. Physiological changes caused by cocaine withdrawal include vivid and unpleasant dreams, insomnia or hypersomnia, increased appetite and psychomotor retardation or agitation.^[49]

Physical side effects from chronic smoking of cocaine include coughing up blood, bronchospasm, itching, fever, diffuse alveolar infiltrates without effusions, pulmonary and systemic eosinophilia, chest pain, lung trauma, sore throat, asthma, hoarse voice, dyspnea (shortness of breath), and an aching, flu-like syndrome. Cocaine constricts blood vessels, dilates pupils, and increases body temperature, heart rate, and blood pressure. It can also cause headaches and gastrointestinal complications such as abdominal pain and nausea. A common but untrue belief is that the smoking of cocaine chemically breaks down tooth enamel and causes tooth decay. However, cocaine does often cause involuntary tooth grinding, known as bruxism, which can deteriorate tooth enamel and lead to gingivitis.^[50] Additionally, stimulants like cocaine, methamphetamine, and even caffeine cause dehydration and dry mouth. Since saliva is an important mechanism in maintaining one's oral pH level, chronic stimulant abusers who do not hydrate sufficiently may experience demineralization of their teeth due to the pH of the tooth surface dropping too low (below 5.5). Cocaine use also promotes the formation of blood clots.^[12] This increase in blood clot formation is attributed to cocaine-associated increases in the activity of plasminogen activator inhibitor, and an increase in the number, activation, and aggregation of platelets.^[12]

Chronic intranasal usage can degrade the cartilage separating the nostrils (the septum nasi), leading eventually to its complete disappearance. Due to the absorption of the cocaine from cocaine hydrochloride, the remaining hydrochloride forms a dilute hydrochloric acid.^[51]

Cocaine may also greatly increase the risk of developing rare autoimmune or connective tissue diseases such as lupus, Goodpasture syndrome, vasculitis, glomerulonephritis, Stevens–Johnson syndrome, and other diseases.^{[52][53][54][55]} It can also cause a wide array of kidney diseases and kidney failure.^[56][57]

Cocaine use leads to an increased risk of hemorrhagic and ischemic strokes.^[29] Cocaine use also increases the risk of having a heart attack.^[58]

Addiction

Cocaine addiction occurs through ΔFosB overexpression in the nucleus accumbens, which results in altered transcriptional regulation in neurons within the nucleus accumbens.

ΔFosB levels have been found to increase upon the use of cocaine.^[59] Each subsequent dose of cocaine continues to increase ΔFosB levels with no ceiling of tolerance. Elevated levels of ΔFosB leads to increases in brain-derived neurotrophic factor (BDNF) levels, which in turn increases the number of dendritic branches and spines present on neurons involved with the nucleus accumbens and prefrontal cortex areas of the brain. This change can be identified rather quickly, and may be sustained weeks after the last dose of the drug.

Transgenic mice exhibiting inducible expression of ΔFosB primarily in the nucleus accumbens and dorsal striatum exhibit sensitized behavioural responses to cocaine.^[60] They self-administer cocaine at lower doses than control,^[61] but have a greater likelihood of relapse when the drug is withheld.^[61][62] ΔFosB increases the expression of AMPA receptor subunit GluR2^[60] and also decreases expression of dynorphin, thereby enhancing sensitivity to reward.^[62]

Dependence and withdrawal

Cocaine dependence is a form of psychological dependence that develops from regular cocaine use and produces a withdrawal state with emotional-motivational deficits upon cessation of cocaine use.

During pregnancy

Cocaine is known to have a number of deleterious effects during pregnancy. Pregnant people who use cocaine have an elevated risk of placental abruption, a condition where the placenta detaches from the uterus and causes bleeding.^[63] Due to its vasoconstrictive and hypertensive effects, they are also at risk for hemorrhagic stroke and myocardial infarction. Cocaine is also teratogenic, meaning that it can cause birth defects and fetal malformations. In-utero exposure to cocaine is associated with behavioral abnormalities, cognitive impairment, cardiovascular malformations, intrauterine growth restriction, preterm birth, urinary tract malformations, and cleft lip and palate.^[64]

Pharmacology

Pharmacodynamics

The pharmacodynamics of cocaine involve the complex relationships of neurotransmitters (inhibiting monoamine uptake in rats with ratios of about: serotonin:dopamine = 2:3, serotonin:norepinephrine = 2:5).^[65][13] The most extensively studied effect of cocaine on the central nervous system is the blockade of the dopamine transporter protein. Dopamine transmitter released during neural signaling is normally recycled via the transporter; i.e., the transporter binds the transmitter and pumps it out of the synaptic cleft back into the presynapticneuron, where it is taken up into storage vesicles. Cocaine binds tightly at the dopamine transporter forming a complex that blocks the transporter's function. The dopamine transporter can no longer perform its reuptake function, and thus dopamine accumulates in the synaptic cleft. The increased concentration of dopamine in the synapse activates post-synaptic dopamine receptors, which makes the drug rewarding and promotes the compulsive use of cocaine.^[66]

Cocaine affects certain serotonin (5-HT) receptors; in particular, it has been shown to antagonize the 5-HT3 receptor, which is a ligand-gated ion channel. The overabundance of 5-HT3 receptors in cocaine conditioned rats display this trait, however the exact effect of 5-HT3 in this process is unclear.^[67] The 5-HT2 receptor (particularly the subtypes 5-HT2A, 5-HT2B and 5-HT2C) are involved in the locomotor-activating effects of cocaine.^[68]

Cocaine has been demonstrated to bind as to directly stabilize the DAT transporter on the open outward-facing conformation. Further, cocaine binds in such a way as to inhibit a hydrogen bond innate to DAT. Cocaine's binding properties are such that it attaches so this hydrogen bond will not form and is blocked from formation due to the tightly locked orientation of the cocaine molecule. Research studies have suggested that the affinity for the transporter is not what is involved in habituation of the substance so much as the conformation and binding properties to where and how on the transporter the molecule binds.^[69]

Sigma receptors are affected by cocaine, as cocaine functions as a sigma ligand agonist.^[70] Further specific receptors it has been demonstrated to function on are NMDA and the D1 dopamine receptor.^[71]

Cocaine also blocks sodium channels, thereby interfering with the propagation of action potentials;^[72][45] thus, like lignocaine and novocaine, it acts as a local anesthetic. It also functions on the binding sites to the dopamine and serotonin sodium dependent transport area as targets as separate mechanisms from its reuptake of those transporters; unique to its local anesthetic value which makes it in a class of functionality different from both its own derived phenyltropanes analogues which have that removed. In addition to this cocaine has some target binding to the site of the Kappa-opioid receptor as well.^[73] Cocaine also causes vasoconstriction, thus reducing bleeding during minor surgical procedures. The locomotor enhancing properties of cocaine may be attributable to its enhancement of dopaminergic transmission from the substantia nigra.^{[citation needed]} Recent research points to an important role of circadian mechanisms^[74] and clock genes^[75] in behavioral actions of cocaine.

Cocaine can often cause reduced food intake, many chronic users lose their appetite and can experience severe malnutrition and significant weight loss. Cocaine effects, further, are shown to be potentiated for the user when used in conjunction with new surroundings and stimuli, and otherwise novel environs.^[76]

Pharmacokinetics

Cocaine has a short half life of 0.7-1.5 hours and is extensively metabolized by cholinesterase enzymes (primarily in the liver and plasma), with only about 1% excreted unchanged in the urine.^[12] The metabolism is dominated by hydrolyticester cleavage, so the eliminated metabolites consist mostly of benzoylecgonine (BE), the major metabolite, and other significant metabolites in lesser amounts such as ecgonine methyl ester (EME) and ecgonine.^[12]