cog/Frameworks/WavPack/Files/open_raw.c

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2020-03-22 07:15:45 +00:00
////////////////////////////////////////////////////////////////////////////
// **** WAVPACK **** //
// Hybrid Lossless Wavefile Compressor //
// Copyright (c) 1998 - 2019 David Bryant. //
// All Rights Reserved. //
// Distributed under the BSD Software License (see license.txt) //
////////////////////////////////////////////////////////////////////////////
// open_raw.c
// This code provides the ability to decode WavPack frames directly from
// memory for use in a streaming application. It can handle full blocks
// or the headerless block data provided by Matroska and the DirectShow
// WavPack splitter. For information about how Matroska stores WavPack,
// see: https://www.matroska.org/technical/specs/codecid/wavpack.html
#include <stdlib.h>
#include <string.h>
#include "wavpack_local.h"
typedef struct {
unsigned char *sptr, *dptr, *eptr, free_required;
} RawSegment;
typedef struct {
RawSegment *segments;
int num_segments, curr_segment;
unsigned char ungetc_char, ungetc_flag;
} WavpackRawContext;
static int32_t raw_read_bytes (void *id, void *data, int32_t bcount)
{
WavpackRawContext *rcxt = id;
unsigned char *outptr = data;
while (bcount) {
if (rcxt->ungetc_flag) {
*outptr++ = rcxt->ungetc_char;
rcxt->ungetc_flag = 0;
bcount--;
}
else if (rcxt->curr_segment < rcxt->num_segments) {
RawSegment *segptr = rcxt->segments + rcxt->curr_segment;
int bytes_to_copy = (int)(segptr->eptr - segptr->dptr);
if (bytes_to_copy > bcount)
bytes_to_copy = bcount;
memcpy (outptr, segptr->dptr, bytes_to_copy);
outptr += bytes_to_copy;
bcount -= bytes_to_copy;
if ((segptr->dptr += bytes_to_copy) == segptr->eptr)
rcxt->curr_segment++;
}
else
break;
}
return (int32_t)(outptr - (unsigned char *) data);
}
static int32_t raw_write_bytes (void *id, void *data, int32_t bcount)
{
return 0;
}
static int64_t raw_get_pos (void *id)
{
return 0;
}
static int raw_set_pos_abs (void *id, int64_t pos)
{
return 0;
}
static int raw_set_pos_rel (void *id, int64_t delta, int mode)
{
return 0;
}
static int raw_push_back_byte (void *id, int c)
{
WavpackRawContext *rcxt = id;
rcxt->ungetc_char = c;
rcxt->ungetc_flag = 1;
return c;
}
static int64_t raw_get_length (void *id)
{
return 0;
}
static int raw_can_seek (void *id)
{
return 0;
}
static int raw_close_stream (void *id)
{
WavpackRawContext *rcxt = id;
int i;
if (rcxt) {
for (i = 0; i < rcxt->num_segments; ++i)
if (rcxt->segments [i].sptr && rcxt->segments [i].free_required)
free (rcxt->segments [i].sptr);
if (rcxt->segments) free (rcxt->segments);
free (rcxt);
}
return 0;
}
static WavpackStreamReader64 raw_reader = {
raw_read_bytes, raw_write_bytes, raw_get_pos, raw_set_pos_abs, raw_set_pos_rel,
raw_push_back_byte, raw_get_length, raw_can_seek, NULL, raw_close_stream
};
// This function is similar to WavpackOpenFileInput() except that instead of
// providing a filename to open, the caller provides pointers to buffered
// WavPack frames (both standard and, optionally, correction data). It
// decodes only a single frame. Note that in this context, a "frame" is a
// collection of WavPack blocks that represent all the channels present. In
// the case of mono or [most] stereo streams, this is the same thing, but
// for multichannel streams each frame consists of several WavPack blocks
// (which can contain only 1 or 2 channels).
WavpackContext *WavpackOpenRawDecoder (
void *main_data, int32_t main_size,
void *corr_data, int32_t corr_size,
int16_t version, char *error, int flags, int norm_offset)
{
WavpackRawContext *raw_wv = NULL, *raw_wvc = NULL;
// if the WavPack data does not contain headers we assume Matroska-style storage
// and recreate the missing headers
if (strncmp (main_data, "wvpk", 4)) {
uint32_t multiple_blocks = 0, block_size, block_samples = 0, wphdr_flags, crc;
uint32_t main_bytes = main_size, corr_bytes = corr_size;
unsigned char *mcp = main_data;
unsigned char *ccp = corr_data;
int msi = 0, csi = 0;
raw_wv = malloc (sizeof (WavpackRawContext));
memset (raw_wv, 0, sizeof (WavpackRawContext));
if (corr_data && corr_size) {
raw_wvc = malloc (sizeof (WavpackRawContext));
memset (raw_wvc, 0, sizeof (WavpackRawContext));
}
while (main_bytes >= 12) {
if (!msi) {
block_samples = *mcp++;
block_samples += *mcp++ << 8;
block_samples += *mcp++ << 16;
block_samples += *mcp++ << 24;
main_bytes -= 4;
}
wphdr_flags = *mcp++;
wphdr_flags += *mcp++ << 8;
wphdr_flags += *mcp++ << 16;
wphdr_flags += *mcp++ << 24;
main_bytes -= 4;
// if the first block does not have the FINAL_BLOCK flag set,
// then there are multiple blocks
if (!msi && !(wphdr_flags & FINAL_BLOCK))
multiple_blocks = 1;
crc = *mcp++;
crc += *mcp++ << 8;
crc += *mcp++ << 16;
crc += *mcp++ << 24;
main_bytes -= 4;
if (multiple_blocks) {
block_size = *mcp++;
block_size += *mcp++ << 8;
block_size += *mcp++ << 16;
block_size += *mcp++ << 24;
main_bytes -= 4;
}
else
block_size = main_bytes;
if (block_size > main_bytes) {
if (error) strcpy (error, "main block overran available data!");
raw_close_stream (raw_wv);
raw_close_stream (raw_wvc);
return NULL;
}
else {
WavpackHeader *wphdr = malloc (sizeof (WavpackHeader));
memset (wphdr, 0, sizeof (WavpackHeader));
memcpy (wphdr->ckID, "wvpk", 4);
wphdr->ckSize = sizeof (WavpackHeader) - 8 + block_size;
SET_TOTAL_SAMPLES (*wphdr, block_samples);
wphdr->block_samples = block_samples;
wphdr->version = version;
wphdr->flags = wphdr_flags;
wphdr->crc = crc;
WavpackLittleEndianToNative (wphdr, WavpackHeaderFormat);
raw_wv->num_segments += 2;
raw_wv->segments = realloc (raw_wv->segments, sizeof (RawSegment) * raw_wv->num_segments);
raw_wv->segments [msi].dptr = raw_wv->segments [msi].sptr = (unsigned char *) wphdr;
raw_wv->segments [msi].eptr = raw_wv->segments [msi].dptr + sizeof (WavpackHeader);
raw_wv->segments [msi++].free_required = 1;
raw_wv->segments [msi].dptr = raw_wv->segments [msi].sptr = mcp;
raw_wv->segments [msi].eptr = raw_wv->segments [msi].dptr + block_size;
raw_wv->segments [msi++].free_required = 0;
main_bytes -= block_size;
mcp += block_size;
}
if (corr_data && corr_bytes >= 4) {
crc = *ccp++;
crc += *ccp++ << 8;
crc += *ccp++ << 16;
crc += *ccp++ << 24;
corr_bytes -= 4;
if (multiple_blocks) {
block_size = *ccp++;
block_size += *ccp++ << 8;
block_size += *ccp++ << 16;
block_size += *ccp++ << 24;
corr_bytes -= 4;
}
else
block_size = corr_bytes;
if (block_size > corr_bytes) {
if (error) strcpy (error, "correction block overran available data!");
raw_close_stream (raw_wv);
raw_close_stream (raw_wvc);
return NULL;
}
else {
WavpackHeader *wphdr = malloc (sizeof (WavpackHeader));
memset (wphdr, 0, sizeof (WavpackHeader));
memcpy (wphdr->ckID, "wvpk", 4);
wphdr->ckSize = sizeof (WavpackHeader) - 8 + block_size;
SET_TOTAL_SAMPLES (*wphdr, block_samples);
wphdr->block_samples = block_samples;
wphdr->version = version;
wphdr->flags = wphdr_flags;
wphdr->crc = crc;
WavpackLittleEndianToNative (wphdr, WavpackHeaderFormat);
raw_wvc->num_segments += 2;
raw_wvc->segments = realloc (raw_wvc->segments, sizeof (RawSegment) * raw_wvc->num_segments);
raw_wvc->segments [csi].dptr = raw_wvc->segments [csi].sptr = (unsigned char *) wphdr;
raw_wvc->segments [csi].eptr = raw_wvc->segments [csi].dptr + sizeof (WavpackHeader);
raw_wvc->segments [csi++].free_required = 1;
raw_wvc->segments [csi].dptr = raw_wvc->segments [csi].sptr = ccp;
raw_wvc->segments [csi].eptr = raw_wvc->segments [csi].dptr + block_size;
raw_wvc->segments [csi++].free_required = 0;
corr_bytes -= block_size;
ccp += block_size;
}
}
}
if (main_bytes || (corr_data && corr_bytes)) {
if (error) strcpy (error, "leftover multiblock data!");
raw_close_stream (raw_wv);
raw_close_stream (raw_wvc);
return NULL;
}
}
else { // the case of WavPack blocks with headers is much easier...
if (main_data) {
raw_wv = malloc (sizeof (WavpackRawContext));
memset (raw_wv, 0, sizeof (WavpackRawContext));
raw_wv->num_segments = 1;
raw_wv->segments = malloc (sizeof (RawSegment) * raw_wv->num_segments);
raw_wv->segments [0].dptr = raw_wv->segments [0].sptr = main_data;
raw_wv->segments [0].eptr = raw_wv->segments [0].dptr + main_size;
raw_wv->segments [0].free_required = 0;
}
if (corr_data && corr_size) {
raw_wvc = malloc (sizeof (WavpackRawContext));
memset (raw_wvc, 0, sizeof (WavpackRawContext));
raw_wvc->num_segments = 1;
raw_wvc->segments = malloc (sizeof (RawSegment) * raw_wvc->num_segments);
raw_wvc->segments [0].dptr = raw_wvc->segments [0].sptr = corr_data;
raw_wvc->segments [0].eptr = raw_wvc->segments [0].dptr + corr_size;
raw_wvc->segments [0].free_required = 0;
}
}
return WavpackOpenFileInputEx64 (&raw_reader, raw_wv, raw_wvc, error, flags | OPEN_STREAMING | OPEN_NO_CHECKSUM, norm_offset);
}
// Return the number of samples represented by the current (and in the raw case, only) frame.
uint32_t WavpackGetNumSamplesInFrame (WavpackContext *wpc)
{
if (wpc && wpc->streams && wpc->streams [0])
return wpc->streams [0]->wphdr.block_samples;
else
return -1;
}