static PyObject*
FlacDecoder_seek(decoders_FlacDecoder* self, PyObject *args)
{
long long seeked_offset;
const array_o* seektable = self->seektable;
uint64_t pcm_frames_offset = 0;
uint64_t byte_offset = 0;
unsigned i;
if (self->closed) {
PyErr_SetString(PyExc_ValueError, "cannot seek closed stream");
return NULL;
}
if (!PyArg_ParseTuple(args, "L", &seeked_offset))
return NULL;
if (seeked_offset < 0) {
PyErr_SetString(PyExc_ValueError, "cannot seek to negative value");
return NULL;
}
self->stream_finalized = 0;
/*find latest seekpoint whose first sample is <= seeked_offset
or 0 if there are no seekpoints in the seektable*/
for (i = 0; i < seektable->len; i++) {
struct flac_SEEKPOINT* seekpoint = seektable->_[i];
if (seekpoint->sample_number <= seeked_offset) {
pcm_frames_offset = seekpoint->sample_number;
byte_offset = seekpoint->byte_offset;
} else {
break;
}
}
/*position bitstream to indicated value in file*/
self->bitstream->rewind(self->bitstream);
while (byte_offset) {
/*perform this in chunks in case seeked distance
is longer than a "long" taken by fseek*/
const uint64_t seek = MIN(byte_offset, LONG_MAX);
fseek(self->file, (long)seek, SEEK_CUR);
byte_offset -= seek;
}
/*reset stream's total remaining frames*/
self->remaining_samples = (self->streaminfo.total_samples -
pcm_frames_offset);
if (pcm_frames_offset == 0) {
/*if pcm_frames_offset is 0, reset MD5 validation*/
audiotools__MD5Init(&(self->md5));
self->perform_validation = 1;
} else {
/*otherwise, disable MD5 validation altogether at end of stream*/
self->perform_validation = 0;
}
/*return actual PCM frames position in file*/
return Py_BuildValue("K", pcm_frames_offset);
}
int
FlacDecoder_init(decoders_FlacDecoder *self,
PyObject *args, PyObject *kwds)
{
char* filename;
int stream_offset = 0;
self->filename = NULL;
self->file = NULL;
self->bitstream = NULL;
self->seektable = array_o_new((ARRAY_COPY_FUNC)seekpoint_copy,
free,
NULL);
self->subframe_data = array_ia_new();
self->residuals = array_i_new();
self->qlp_coeffs = array_i_new();
self->framelist_data = array_i_new();
self->audiotools_pcm = NULL;
self->remaining_samples = 0;
if (!PyArg_ParseTuple(args, "si|i",
&filename,
&(self->channel_mask),
&stream_offset))
return -1;
if (self->channel_mask < 0) {
PyErr_SetString(PyExc_ValueError, "channel_mask must be >= 0");
return -1;
}
if (stream_offset < 0) {
PyErr_SetString(PyExc_ValueError, "stream offset must be >= 0");
return -1;
}
/*open the flac file*/
self->file = fopen(filename, "rb");
if (self->file == NULL) {
PyErr_SetFromErrnoWithFilename(PyExc_IOError, filename);
return -1;
} else {
self->bitstream = br_open(self->file, BS_BIG_ENDIAN);
}
/*skip the given number of bytes, if any*/
if (stream_offset != 0)
fseek(self->file, stream_offset, SEEK_SET);
self->filename = strdup(filename);
/*read the STREAMINFO block, SEEKTABLE block
and setup the total number of samples to read*/
if (flacdec_read_metadata(self->bitstream,
&(self->streaminfo),
self->seektable)) {
self->streaminfo.channels = 0;
return -1;
}
self->remaining_samples = self->streaminfo.total_samples;
/*initialize the output MD5 sum*/
audiotools__MD5Init(&(self->md5));
self->perform_validation = 1;
self->stream_finalized = 0;
/*setup a framelist generator function*/
if ((self->audiotools_pcm = open_audiotools_pcm()) == NULL)
return -1;
/*place mark at beginning of stream in case seeking is needed*/
self->bitstream->mark(self->bitstream);
/*mark stream as not closed and ready for reading*/
self->closed = 0;
return 0;
}
int
OggFlacDecoder_init(decoders_OggFlacDecoder *self,
PyObject *args, PyObject *kwds) {
char* filename;
ogg_status result;
uint16_t header_packets;
self->ogg_stream = NULL;
self->ogg_file = NULL;
self->subframe_data = aa_int_new();
self->residuals = a_int_new();
self->qlp_coeffs = a_int_new();
self->framelist_data = a_int_new();
self->audiotools_pcm = NULL;
self->packet = br_substream_new(BS_BIG_ENDIAN);
self->stream_finalized = 0;
if (!PyArg_ParseTuple(args, "si", &filename, &(self->channel_mask)))
return -1;
if (self->channel_mask < 0) {
PyErr_SetString(PyExc_ValueError, "channel_mask must be >= 0");
return -1;
}
self->ogg_file = fopen(filename, "rb");
if (self->ogg_file == NULL) {
PyErr_SetFromErrnoWithFilename(PyExc_IOError, filename);
return -1;
} else {
self->ogg_stream = oggreader_open(self->ogg_file);
}
/*the first packet should be the FLAC's STREAMINFO*/
if ((result = oggreader_next_packet(self->ogg_stream,
self->packet)) == OGG_OK) {
if (!oggflac_read_streaminfo(self->packet,
&(self->streaminfo),
&header_packets))
return -1;
} else {
PyErr_SetString(ogg_exception(result), ogg_strerror(result));
return -1;
}
/*skip subsequent header packets*/
for (; header_packets > 0; header_packets--) {
if ((result = oggreader_next_packet(self->ogg_stream,
self->packet)) != OGG_OK) {
PyErr_SetString(ogg_exception(result), ogg_strerror(result));
return -1;
}
}
/*initialize the output MD5 sum*/
audiotools__MD5Init(&(self->md5));
/*add callback for CRC16 calculation*/
br_add_callback(self->packet, (bs_callback_f)flac_crc16, &(self->crc16));
/*setup a framelist generator function*/
if ((self->audiotools_pcm = open_audiotools_pcm()) == NULL)
return -1;
/*mark stream as not closed and ready for reading*/
self->closed = 0;
return 0;
}
int
FlacDecoder_init(decoders_FlacDecoder *self,
PyObject *args, PyObject *kwds)
{
self->file = NULL;
self->bitstream = NULL;
self->seektable = a_obj_new((ARRAY_COPY_FUNC)seekpoint_copy,
free,
NULL);
self->subframe_data = aa_int_new();
self->residuals = a_int_new();
self->qlp_coeffs = a_int_new();
self->framelist_data = a_int_new();
self->audiotools_pcm = NULL;
self->remaining_samples = 0;
if (!PyArg_ParseTuple(args, "O", &self->file)) {
return -1;
} else {
Py_INCREF(self->file);
}
/*open BitstreamReader from FLAC file stream
based on whether it's a low-level file object*/
if (PyFile_Check(self->file)) {
/*open bitstream through file object*/
self->bitstream = br_open(PyFile_AsFile(self->file), BS_BIG_ENDIAN);
} else {
/*treat file as Python-implemented file-like object*/
self->bitstream = br_open_external(
self->file,
BS_BIG_ENDIAN,
4096,
(ext_read_f)br_read_python,
(ext_close_f)bs_close_python,
(ext_free_f)bs_free_python_nodecref);
}
/*read the STREAMINFO block, SEEKTABLE block
and setup the total number of samples to read*/
if (flacdec_read_metadata(self->bitstream,
&(self->streaminfo),
self->seektable,
&(self->channel_mask))) {
self->streaminfo.channels = 0;
return -1;
}
if (PyFile_Check(self->file)) {
/*place mark at beginning of stream but after metadata
in case seeking is needed*/
self->bitstream->mark(self->bitstream);
}
self->remaining_samples = self->streaminfo.total_samples;
/*initialize the output MD5 sum*/
audiotools__MD5Init(&(self->md5));
self->perform_validation = 1;
self->stream_finalized = 0;
/*setup a framelist generator function*/
if ((self->audiotools_pcm = open_audiotools_pcm()) == NULL)
return -1;
/*mark stream as not closed and ready for reading*/
self->closed = 0;
return 0;
}
int main(int argc, char* argv[]) {
FILE* ogg_file;
OggReader* ogg_stream = NULL;
BitstreamReader* packet = NULL;
struct flac_STREAMINFO streaminfo;
uint16_t header_packets;
a_int* residuals = NULL;
a_int* qlp_coeffs = NULL;
aa_int* subframe_data = NULL;
a_int* framelist_data = NULL;
ogg_status result;
uint16_t crc16 = 0;
FrameList_int_to_char_converter converter;
unsigned pcm_size;
unsigned output_data_size = 1;
uint8_t* output_data = NULL;
audiotools__MD5Context md5;
unsigned char stream_md5sum[16];
const static unsigned char blank_md5sum[16] = {0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0};
if (argc < 2) {
fprintf(stderr, "*** Usage: %s <file.oga>\n", argv[0]);
return 1;
}
/*open input file for reading*/
if ((ogg_file = fopen(argv[1], "rb")) == NULL) {
fprintf(stderr, "*** %s: %s\n", argv[1], strerror(errno));
return 1;
} else {
/*open bitstream and setup temporary arrays/buffers*/
ogg_stream = oggreader_open(ogg_file);
packet = br_substream_new(BS_BIG_ENDIAN);
subframe_data = aa_int_new();
residuals = a_int_new();
qlp_coeffs = a_int_new();
framelist_data = a_int_new();
output_data = malloc(output_data_size);
}
/*the first packet should be the FLAC's STREAMINFO*/
if ((result = oggreader_next_packet(ogg_stream, packet)) == OGG_OK) {
if (!oggflac_read_streaminfo(packet, &streaminfo, &header_packets)) {
goto error;
} else {
converter = FrameList_get_int_to_char_converter(
streaminfo.bits_per_sample, 0, 1);
}
} else {
fprintf(stderr, "*** Error: %s\n", ogg_strerror(result));
goto error;
}
/*skip subsequent header packets*/
for (; header_packets > 0; header_packets--) {
if ((result = oggreader_next_packet(ogg_stream, packet)) != OGG_OK) {
fprintf(stderr, "*** Error: %s\n", ogg_strerror(result));
goto error;
}
}
/*initialize the output MD5 sum*/
audiotools__MD5Init(&md5);
/*add callback for CRC16 calculation*/
br_add_callback(packet, (bs_callback_f)flac_crc16, &crc16);
/*decode the next FrameList from the stream*/
result = oggreader_next_packet(ogg_stream, packet);
while (result != OGG_STREAM_FINISHED) {
if (result == OGG_OK) {
flac_status flac_status;
struct flac_frame_header frame_header;
unsigned channel;
subframe_data->reset(subframe_data);
if (!setjmp(*br_try(packet))) {
/*read frame header*/
if ((flac_status =
flacdec_read_frame_header(packet,
&streaminfo,
&frame_header)) != OK) {
fprintf(stderr, "*** Error: %s\n",
FlacDecoder_strerror(flac_status));
br_etry(packet);
goto error;
}
/*read 1 subframe per channel*/
for (channel = 0;
channel < frame_header.channel_count;
channel++)
if ((flac_status = flacdec_read_subframe(
packet,
qlp_coeffs,
residuals,
frame_header.block_size,
flacdec_subframe_bits_per_sample(&frame_header,
channel),
subframe_data->append(subframe_data))) != OK) {
fprintf(stderr, "*** Error: %s\n",
FlacDecoder_strerror(flac_status));
br_etry(packet);
goto error;
}
br_etry(packet);
} else {
br_etry(packet);
fprintf(stderr, "*** I/O Error reading FLAC frame\n");
goto error;
}
/*handle difference channels, if any*/
flacdec_decorrelate_channels(frame_header.channel_assignment,
subframe_data,
framelist_data);
/*check CRC-16*/
packet->byte_align(packet);
packet->read(packet, 16);
if (crc16 != 0) {
fprintf(stderr, "*** Error: invalid checksum in frame\n");
goto error;
}
/*turn FrameList into string of output*/
pcm_size = (streaminfo.bits_per_sample / 8) * framelist_data->len;
if (pcm_size > output_data_size) {
output_data_size = pcm_size;
output_data = realloc(output_data, output_data_size);
}
FrameList_samples_to_char(output_data,
framelist_data->_,
converter,
framelist_data->len,
streaminfo.bits_per_sample);
/*update MD5 sum*/
audiotools__MD5Update(&md5, output_data, pcm_size);
/*output string to stdout*/
fwrite(output_data, sizeof(unsigned char), pcm_size, stdout);
result = oggreader_next_packet(ogg_stream, packet);
} else {
/*some error reading Ogg stream*/
fprintf(stderr, "*** Error: %s\n", ogg_strerror(result));
goto error;
}
}
/*Ogg stream is finished so verify stream's MD5 sum*/
audiotools__MD5Final(stream_md5sum, &md5);
if (!((memcmp(streaminfo.md5sum, blank_md5sum, 16) == 0) ||
(memcmp(stream_md5sum, streaminfo.md5sum, 16) == 0))) {
fprintf(stderr, "*** MD5 mismatch at end of stream\n");
goto error;
}
/*close streams, temporary buffers*/
oggreader_close(ogg_stream);
packet->close(packet);
subframe_data->del(subframe_data);
residuals->del(residuals);
qlp_coeffs->del(qlp_coeffs);
framelist_data->del(framelist_data);
free(output_data);
return 0;
error:
oggreader_close(ogg_stream);
packet->close(packet);
subframe_data->del(subframe_data);
residuals->del(residuals);
qlp_coeffs->del(qlp_coeffs);
framelist_data->del(framelist_data);
free(output_data);
return 1;
}
