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////////////////////////////////////////////////////////////////////////////
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// **** WAVPACK **** //
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// Hybrid Lossless Wavefile Compressor //
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// Copyright (c) 1998 - 2006 Conifer Software. //
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// All Rights Reserved. //
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// Distributed under the BSD Software License (see license.txt) //
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////////////////////////////////////////////////////////////////////////////
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// This module provides a high-level interface for decoding WavPack 4.0 audio
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// streams and files. WavPack data is read with a stream reading callback. No
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// direct seeking is provided for, but it is possible to start decoding
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// anywhere in a WavPack stream. In this case, WavPack will be able to provide
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// the sample-accurate position when it synchs with the data and begins
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///////////////////////////// local table storage ////////////////////////////
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const uint32_t sample_rates [] = { 6000, 8000, 9600, 11025, 12000, 16000, 22050,
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24000, 32000, 44100, 48000, 64000, 88200, 96000, 192000 };
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///////////////////////////// executable code ////////////////////////////////
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static uint32_t read_next_header (read_stream infile, WavpackHeader *wphdr);
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// This function reads data from the specified stream in search of a valid
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// WavPack 4.0 audio block. If this fails in 1 megabyte (or an invalid or
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// unsupported WavPack block is encountered) then an appropriate message is
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// copied to "error" and NULL is returned, otherwise a pointer to a
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// WavpackContext structure is returned (which is used to call all other
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// functions in this module). This can be initiated at the beginning of a
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// WavPack file, or anywhere inside a WavPack file. To determine the exact
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// position within the file use WavpackGetSampleIndex(). For demonstration
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// purposes this uses a single static copy of the WavpackContext structure,
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// so obviously it cannot be used for more than one file at a time. Also,
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// this function will not handle "correction" files, plays only the first
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// two channels of multi-channel files, and is limited in resolution in some
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// large integer or floating point files (but always provides at least 24 bits
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static WavpackContext wpc;
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WavpackContext *WavpackOpenFileInput (read_stream infile, char *error)
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WavpackStream *wps = &wpc.stream;
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wpc.total_samples = (uint32_t) -1;
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// open the source file for reading and store the size
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while (!wps->wphdr.block_samples) {
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bcount = read_next_header (wpc.infile, &wps->wphdr);
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if (bcount == (uint32_t) -1) {
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strcpy (error, "not compatible with this version of WavPack file!");
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if (wps->wphdr.block_samples && wps->wphdr.total_samples != (uint32_t) -1)
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wpc.total_samples = wps->wphdr.total_samples;
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if (!unpack_init (&wpc)) {
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strcpy (error, wpc.error_message [0] ? wpc.error_message :
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"not compatible with this version of WavPack file!");
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wpc.config.flags &= ~0xff;
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wpc.config.flags |= wps->wphdr.flags & 0xff;
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wpc.config.bytes_per_sample = (wps->wphdr.flags & BYTES_STORED) + 1;
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wpc.config.float_norm_exp = wps->float_norm_exp;
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wpc.config.bits_per_sample = (wpc.config.bytes_per_sample * 8) -
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((wps->wphdr.flags & SHIFT_MASK) >> SHIFT_LSB);
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if (wpc.config.flags & FLOAT_DATA) {
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wpc.config.bytes_per_sample = 3;
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wpc.config.bits_per_sample = 24;
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if (!wpc.config.sample_rate) {
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if (!wps || !wps->wphdr.block_samples || (wps->wphdr.flags & SRATE_MASK) == SRATE_MASK)
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wpc.config.sample_rate = 44100;
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wpc.config.sample_rate = sample_rates [(wps->wphdr.flags & SRATE_MASK) >> SRATE_LSB];
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if (!wpc.config.num_channels) {
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wpc.config.num_channels = (wps->wphdr.flags & MONO_FLAG) ? 1 : 2;
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wpc.config.channel_mask = 0x5 - wpc.config.num_channels;
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if (!(wps->wphdr.flags & FINAL_BLOCK))
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wpc.reduced_channels = (wps->wphdr.flags & MONO_FLAG) ? 1 : 2;
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// This function obtains general information about an open file and returns
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// a mask with the following bit values:
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// MODE_LOSSLESS: file is lossless (pure lossless only)
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// MODE_HYBRID: file is hybrid mode (lossy part only)
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// MODE_FLOAT: audio data is 32-bit ieee floating point (but will provided
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// in 24-bit integers for convenience)
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// MODE_HIGH: file was created in "high" mode (information only)
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// MODE_FAST: file was created in "fast" mode (information only)
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int WavpackGetMode (WavpackContext *wpc)
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if (wpc->config.flags & CONFIG_HYBRID_FLAG)
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else if (!(wpc->config.flags & CONFIG_LOSSY_MODE))
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mode |= MODE_LOSSLESS;
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if (wpc->lossy_blocks)
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mode &= ~MODE_LOSSLESS;
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if (wpc->config.flags & CONFIG_FLOAT_DATA)
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if (wpc->config.flags & CONFIG_HIGH_FLAG)
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if (wpc->config.flags & CONFIG_FAST_FLAG)
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// Unpack the specified number of samples from the current file position.
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// Note that "samples" here refers to "complete" samples, which would be
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// 2 longs for stereo files. The audio data is returned right-justified in
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// 32-bit longs in the endian mode native to the executing processor. So,
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// if the original data was 16-bit, then the values returned would be
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// +/-32k. Floating point data will be returned as 24-bit integers (and may
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// also be clipped). The actual number of samples unpacked is returned,
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// which should be equal to the number requested unless the end of fle is
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// encountered or an error occurs.
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uint32_t WavpackUnpackSamples (WavpackContext *wpc, int32_t *buffer, uint32_t samples)
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WavpackStream *wps = &wpc->stream;
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uint32_t bcount, samples_unpacked = 0, samples_to_unpack;
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int num_channels = wpc->config.num_channels;
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if (!wps->wphdr.block_samples || !(wps->wphdr.flags & INITIAL_BLOCK) ||
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wps->sample_index >= wps->wphdr.block_index + wps->wphdr.block_samples) {
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bcount = read_next_header (wpc->infile, &wps->wphdr);
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if (bcount == (uint32_t) -1)
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if (!wps->wphdr.block_samples || wps->sample_index == wps->wphdr.block_index)
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if (!unpack_init (wpc))
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if (!wps->wphdr.block_samples || !(wps->wphdr.flags & INITIAL_BLOCK) ||
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wps->sample_index >= wps->wphdr.block_index + wps->wphdr.block_samples)
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if (wps->sample_index < wps->wphdr.block_index) {
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samples_to_unpack = wps->wphdr.block_index - wps->sample_index;
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if (samples_to_unpack > samples)
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samples_to_unpack = samples;
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wps->sample_index += samples_to_unpack;
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samples_unpacked += samples_to_unpack;
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samples -= samples_to_unpack;
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if (wpc->reduced_channels)
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samples_to_unpack *= wpc->reduced_channels;
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samples_to_unpack *= num_channels;
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while (samples_to_unpack--)
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samples_to_unpack = wps->wphdr.block_index + wps->wphdr.block_samples - wps->sample_index;
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if (samples_to_unpack > samples)
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samples_to_unpack = samples;
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unpack_samples (wpc, buffer, samples_to_unpack);
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if (wpc->reduced_channels)
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buffer += samples_to_unpack * wpc->reduced_channels;
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buffer += samples_to_unpack * num_channels;
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samples_unpacked += samples_to_unpack;
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samples -= samples_to_unpack;
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if (wps->sample_index == wps->wphdr.block_index + wps->wphdr.block_samples) {
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if (check_crc_error (wpc))
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if (wps->sample_index == wpc->total_samples)
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return samples_unpacked;
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// Get total number of samples contained in the WavPack file, or -1 if unknown
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uint32_t WavpackGetNumSamples (WavpackContext *wpc)
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return wpc ? wpc->total_samples : (uint32_t) -1;
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// Get the current sample index position, or -1 if unknown
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uint32_t WavpackGetSampleIndex (WavpackContext *wpc)
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return wpc->stream.sample_index;
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return (uint32_t) -1;
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// Get the number of errors encountered so far
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int WavpackGetNumErrors (WavpackContext *wpc)
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return wpc ? wpc->crc_errors : 0;
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// return TRUE if any uncorrected lossy blocks were actually written or read
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int WavpackLossyBlocks (WavpackContext *wpc)
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return wpc ? wpc->lossy_blocks : 0;
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// Returns the sample rate of the specified WavPack file
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uint32_t WavpackGetSampleRate (WavpackContext *wpc)
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return wpc ? wpc->config.sample_rate : 44100;
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// Returns the number of channels of the specified WavPack file. Note that
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// this is the actual number of channels contained in the file, but this
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// version can only decode the first two.
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int WavpackGetNumChannels (WavpackContext *wpc)
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return wpc ? wpc->config.num_channels : 2;
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// Returns the actual number of valid bits per sample contained in the
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// original file, which may or may not be a multiple of 8. Floating data
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// always has 32 bits, integers may be from 1 to 32 bits each. When this
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// value is not a multiple of 8, then the "extra" bits are located in the
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// LSBs of the results. That is, values are right justified when unpacked
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// into longs, but are left justified in the number of bytes used by the
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int WavpackGetBitsPerSample (WavpackContext *wpc)
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return wpc ? wpc->config.bits_per_sample : 16;
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// Returns the number of bytes used for each sample (1 to 4) in the original
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// file. This is required information for the user of this module because the
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// audio data is returned in the LOWER bytes of the long buffer and must be
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// left-shifted 8, 16, or 24 bits if normalized longs are required.
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int WavpackGetBytesPerSample (WavpackContext *wpc)
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return wpc ? wpc->config.bytes_per_sample : 2;
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// This function will return the actual number of channels decoded from the
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// file (which may or may not be less than the actual number of channels, but
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// will always be 1 or 2). Normally, this will be the front left and right
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// channels of a multi-channel file.
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int WavpackGetReducedChannels (WavpackContext *wpc)
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return wpc->reduced_channels ? wpc->reduced_channels : wpc->config.num_channels;
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// Read from current file position until a valid 32-byte WavPack 4.0 header is
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// found and read into the specified pointer. The number of bytes skipped is
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// returned. If no WavPack header is found within 1 meg, then a -1 is returned
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// to indicate the error. No additional bytes are read past the header and it
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// is returned in the processor's native endian mode. Seeking is not required.
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static uint32_t read_next_header (read_stream infile, WavpackHeader *wphdr)
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char buffer [sizeof (*wphdr)], *sp = buffer + sizeof (*wphdr), *ep = sp;
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uint32_t bytes_skipped = 0;
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memcpy (buffer, sp, bleft);
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if (infile (buffer + bleft, sizeof (*wphdr) - bleft) != (int32_t) sizeof (*wphdr) - bleft)
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if (*sp++ == 'w' && *sp == 'v' && *++sp == 'p' && *++sp == 'k' &&
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!(*++sp & 1) && sp [2] < 16 && !sp [3] && sp [5] == 4 &&
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sp [4] >= (MIN_STREAM_VERS & 0xff) && sp [4] <= (MAX_STREAM_VERS & 0xff)) {
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memcpy (wphdr, buffer, sizeof (*wphdr));
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little_endian_to_native (wphdr, WavpackHeaderFormat);
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return bytes_skipped;
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while (sp < ep && *sp != 'w')
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if ((bytes_skipped += sp - buffer) > 1048576L)
added
removed
src/engine/external/wavpack/wputils.c
