OggReader*
oggreader_open(FILE *stream) {
OggReader *reader = malloc(sizeof(OggReader));
reader->ogg_stream = br_open(stream, BS_LITTLE_ENDIAN);
reader->current_segment = 1;
reader->current_header.page_segment_count = 0;
reader->current_header.type = 0;
reader->current_header.checksum = 0;
reader->checksum = 0;
br_add_callback(reader->ogg_stream, ogg_crc, &(reader->checksum));
return reader;
}
flac_status
flacdec_read_frame_header(BitstreamReader *bitstream,
struct flac_STREAMINFO *streaminfo,
struct flac_frame_header *header)
{
unsigned block_size_bits;
unsigned sample_rate_bits;
uint8_t crc8 = 0;
br_add_callback(bitstream, (bs_callback_f)flac_crc8, &crc8);
/*read and verify sync code*/
if (bitstream->read(bitstream, 14) != 0x3FFE) {
return ERR_INVALID_SYNC_CODE;
}
/*read and verify reserved bit*/
if (bitstream->read(bitstream, 1) != 0) {
return ERR_INVALID_RESERVED_BIT;
}
header->blocking_strategy = bitstream->read(bitstream, 1);
block_size_bits = bitstream->read(bitstream, 4);
sample_rate_bits = bitstream->read(bitstream, 4);
header->channel_assignment = bitstream->read(bitstream, 4);
switch (header->channel_assignment) {
case 0x8:
case 0x9:
case 0xA:
header->channel_count = 2;
break;
default:
header->channel_count = header->channel_assignment + 1;
break;
}
switch (bitstream->read(bitstream, 3)) {
case 0:
header->bits_per_sample = streaminfo->bits_per_sample; break;
case 1:
header->bits_per_sample = 8; break;
case 2:
header->bits_per_sample = 12; break;
case 4:
header->bits_per_sample = 16; break;
case 5:
header->bits_per_sample = 20; break;
case 6:
header->bits_per_sample = 24; break;
default:
return ERR_INVALID_BITS_PER_SAMPLE;
}
bitstream->read(bitstream, 1); /*padding*/
header->frame_number = read_utf8(bitstream);
switch (block_size_bits) {
case 0x0: header->block_size = streaminfo->maximum_block_size; break;
case 0x1: header->block_size = 192; break;
case 0x2: header->block_size = 576; break;
case 0x3: header->block_size = 1152; break;
case 0x4: header->block_size = 2304; break;
case 0x5: header->block_size = 4608; break;
case 0x6: header->block_size = bitstream->read(bitstream, 8) + 1; break;
case 0x7: header->block_size = bitstream->read(bitstream, 16) + 1; break;
case 0x8: header->block_size = 256; break;
case 0x9: header->block_size = 512; break;
case 0xA: header->block_size = 1024; break;
case 0xB: header->block_size = 2048; break;
case 0xC: header->block_size = 4096; break;
case 0xD: header->block_size = 8192; break;
case 0xE: header->block_size = 16384; break;
case 0xF: header->block_size = 32768; break;
}
switch (sample_rate_bits) {
case 0x0: header->sample_rate = streaminfo->sample_rate; break;
case 0x1: header->sample_rate = 88200; break;
case 0x2: header->sample_rate = 176400; break;
case 0x3: header->sample_rate = 192000; break;
case 0x4: header->sample_rate = 8000; break;
case 0x5: header->sample_rate = 16000; break;
case 0x6: header->sample_rate = 22050; break;
case 0x7: header->sample_rate = 24000; break;
case 0x8: header->sample_rate = 32000; break;
case 0x9: header->sample_rate = 44100; break;
case 0xA: header->sample_rate = 48000; break;
case 0xB: header->sample_rate = 96000; break;
case 0xC: header->sample_rate = bitstream->read(bitstream, 8) * 1000; break;
case 0xD: header->sample_rate = bitstream->read(bitstream, 16); break;
case 0xE: header->sample_rate = bitstream->read(bitstream, 16) * 10; break;
case 0xF:
return ERR_INVALID_SAMPLE_RATE;
}
/*check for valid CRC-8 value*/
bitstream->read(bitstream, 8);
br_pop_callback(bitstream, NULL);
if (crc8 != 0)
return ERR_INVALID_FRAME_CRC;
/*Once we've read everything,
ensure the values are compatible with STREAMINFO.*/
if (streaminfo->sample_rate != header->sample_rate) {
return ERR_SAMPLE_RATE_MISMATCH;
}
if (streaminfo->channels != header->channel_count) {
return ERR_CHANNEL_COUNT_MISMATCH;
}
if (streaminfo->bits_per_sample != header->bits_per_sample) {
return ERR_BITS_PER_SAMPLE_MISMATCH;
}
if (header->block_size > streaminfo->maximum_block_size) {
return ERR_MAXIMUM_BLOCK_SIZE_EXCEEDED;
}
return OK;
}
PyObject*
FlacDecoder_read(decoders_FlacDecoder* self, PyObject *args)
{
uint16_t crc16 = 0;
int channel;
struct flac_frame_header frame_header;
PyObject* framelist;
PyThreadState *thread_state;
flac_status error;
if (self->closed) {
PyErr_SetString(PyExc_ValueError, "cannot read closed stream");
return NULL;
}
self->subframe_data->reset(self->subframe_data);
/*if all samples have been read, return an empty FrameList*/
if (self->stream_finalized) {
return empty_FrameList(self->audiotools_pcm,
self->streaminfo.channels,
self->streaminfo.bits_per_sample);
}
if (self->remaining_samples < 1) {
self->stream_finalized = 1;
if (FlacDecoder_verify_okay(self)) {
return empty_FrameList(self->audiotools_pcm,
self->streaminfo.channels,
self->streaminfo.bits_per_sample);
} else {
PyErr_SetString(PyExc_ValueError,
"MD5 mismatch at end of stream");
return NULL;
}
}
thread_state = PyEval_SaveThread();
if (!setjmp(*br_try(self->bitstream))) {
/*add callback for CRC16 calculation*/
br_add_callback(self->bitstream, (bs_callback_f)flac_crc16, &crc16);
/*read frame header*/
if ((error = flacdec_read_frame_header(self->bitstream,
&(self->streaminfo),
&frame_header)) != OK) {
br_pop_callback(self->bitstream, NULL);
PyEval_RestoreThread(thread_state);
PyErr_SetString(PyExc_ValueError, FlacDecoder_strerror(error));
br_etry(self->bitstream);
return NULL;
}
/*read 1 subframe per channel*/
for (channel = 0; channel < frame_header.channel_count; channel++)
if ((error =
flacdec_read_subframe(
self->bitstream,
self->qlp_coeffs,
self->residuals,
(unsigned int)MIN(frame_header.block_size,
self->remaining_samples),
flacdec_subframe_bits_per_sample(&frame_header,
channel),
self->subframe_data->append(self->subframe_data))) != OK) {
br_pop_callback(self->bitstream, NULL);
PyEval_RestoreThread(thread_state);
PyErr_SetString(PyExc_ValueError, FlacDecoder_strerror(error));
br_etry(self->bitstream);
return NULL;
}
/*handle difference channels, if any*/
flacdec_decorrelate_channels(frame_header.channel_assignment,
self->subframe_data,
self->framelist_data);
/*check CRC-16*/
self->bitstream->byte_align(self->bitstream);
self->bitstream->read(self->bitstream, 16);
br_pop_callback(self->bitstream, NULL);
if (crc16 != 0) {
PyEval_RestoreThread(thread_state);
PyErr_SetString(PyExc_ValueError, "invalid checksum in frame");
br_etry(self->bitstream);
return NULL;
}
/*decrement remaining samples*/
self->remaining_samples -= frame_header.block_size;
} else {
/*handle I/O error during read*/
br_pop_callback(self->bitstream, NULL);
PyEval_RestoreThread(thread_state);
PyErr_SetString(PyExc_IOError, "EOF reading frame");
br_etry(self->bitstream);
return NULL;
}
br_etry(self->bitstream);
PyEval_RestoreThread(thread_state);
framelist = array_i_to_FrameList(self->audiotools_pcm,
self->framelist_data,
frame_header.channel_count,
frame_header.bits_per_sample);
if (framelist != NULL) {
/*update MD5 sum*/
if (FlacDecoder_update_md5sum(self, framelist) == OK)
/*return pcm.FrameList Python object*/
return framelist;
else {
Py_DECREF(framelist);
return NULL;
}
} else {
return NULL;
}
}
static PyObject*
FlacDecoder_offsets(decoders_FlacDecoder* self, PyObject *args)
{
int channel;
struct flac_frame_header frame_header;
flac_status error;
PyObject* offsets = PyList_New(0);
PyObject* offset_pair;
unsigned long long total_offset = 0;
unsigned samples;
unsigned long long offset;
br_add_callback(self->bitstream,
(bs_callback_f)increment_offset,
&total_offset);
while (self->remaining_samples > 0) {
self->subframe_data->reset(self->subframe_data);
offset = total_offset;
if (!setjmp(*br_try(self->bitstream))) {
/*read frame header*/
if ((error = flacdec_read_frame_header(self->bitstream,
&(self->streaminfo),
&frame_header)) != OK) {
PyErr_SetString(PyExc_ValueError, FlacDecoder_strerror(error));
goto error;
}
samples = frame_header.block_size;
/*read 1 subframe per channel*/
for (channel = 0; channel < frame_header.channel_count; channel++)
if ((error =
flacdec_read_subframe(
self->bitstream,
self->qlp_coeffs,
self->residuals,
(unsigned int)MIN(frame_header.block_size,
self->remaining_samples),
flacdec_subframe_bits_per_sample(&frame_header,
channel),
self->subframe_data->append(self->subframe_data))) !=
OK) {
PyErr_SetString(PyExc_ValueError,
FlacDecoder_strerror(error));
goto error;
}
/*read CRC-16*/
self->bitstream->byte_align(self->bitstream);
self->bitstream->read(self->bitstream, 16);
/*decrement remaining samples*/
self->remaining_samples -= frame_header.block_size;
/*add offset pair to our list*/
offset_pair = Py_BuildValue("(K, I)", offset, samples);
PyList_Append(offsets, offset_pair);
Py_DECREF(offset_pair);
} else {
/*handle I/O error during read*/
PyErr_SetString(PyExc_IOError, "EOF reading frame");
goto error;
}
br_etry(self->bitstream);
}
self->stream_finalized = 1;
br_pop_callback(self->bitstream, NULL);
return offsets;
error:
Py_XDECREF(offsets);
br_etry(self->bitstream);
br_pop_callback(self->bitstream, NULL);
return NULL;
}
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 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;
}
PyObject*
verifymodule_ogg(PyObject *dummy, PyObject *args) {
PyObject *file_obj;
BitstreamReader *bitstream;
int has_previous_header = 0;
struct ogg_header previous_header;
struct ogg_header header;
uint8_t *data_buffer = NULL;
int data_buffer_size = 0;
int i;
uint32_t checksum;
/*fixes a "may be used unitialized" warning*/
previous_header.bitstream_serial_number =
previous_header.page_sequence_number = 0;
if (!PyArg_ParseTuple(args, "O", &file_obj))
return NULL;
if (!PyFile_CheckExact(file_obj)) {
PyErr_SetString(PyExc_TypeError,
"first argument must be an actual file object");
return NULL;
} else {
bitstream = br_open(PyFile_AsFile(file_obj), BS_LITTLE_ENDIAN);
br_add_callback(bitstream, ogg_crc, &checksum);
}
if (!setjmp(*br_try(bitstream))) {
do {
checksum = 0;
if (verifymodule_read_ogg_header(bitstream, &header) == OK) {
if (data_buffer_size < header.segment_length_total) {
data_buffer = realloc(data_buffer,
header.segment_length_total);
data_buffer_size = header.segment_length_total;
}
if (fread(data_buffer,
sizeof(uint8_t),
header.segment_length_total,
bitstream->input.file) !=
header.segment_length_total) {
PyErr_SetString(PyExc_IOError, "I/O error reading stream");
goto error;
}
for (i = 0; i < header.segment_length_total; i++)
ogg_crc(data_buffer[i], &checksum);
if (header.checksum != checksum) {
PyErr_SetString(PyExc_ValueError,
"checksum mismatch in stream");
goto error;
}
/* printf("calculated checksum : 0x%8.8X\n", checksum); */
if (has_previous_header) {
if (header.bitstream_serial_number !=
previous_header.bitstream_serial_number) {
PyErr_SetString(PyExc_ValueError,
"differing serial numbers in stream");
goto error;
}
if (header.page_sequence_number !=
(previous_header.page_sequence_number + 1)) {
PyErr_SetString(PyExc_ValueError,
"page sequence number not incrementing");
goto error;
}
previous_header = header;
} else {
previous_header = header;
has_previous_header = 1;
}
} else {
goto error;
}
} while (!(header.type & 0x4));
} else {
PyErr_SetString(PyExc_IOError, "I/O error reading stream");
goto error;
}
br_etry(bitstream);
free(data_buffer);
bitstream->input.file = NULL;
bitstream->free(bitstream);
Py_INCREF(Py_None);
return Py_None;
error:
br_etry(bitstream);
if (data_buffer != NULL)
free(data_buffer);
bitstream->input.file = NULL;
bitstream->free(bitstream);
return NULL;
}
