static int sox_mp3seek(sox_format_t * ft, uint64_t offset)
{
priv_t * p = (priv_t *) ft->priv;
size_t initial_bitrate = p->Frame.header.bitrate;
size_t tagsize = 0, consumed = 0;
sox_bool vbr = sox_false; /* Variable Bit Rate */
sox_bool depadded = sox_false;
uint64_t to_skip_samples = 0;
/* Reset all */
lsx_rewind(ft);
mad_timer_reset(&p->Timer);
p->FrameCount = 0;
/* They where opened in startread */
mad_synth_finish(&p->Synth);
p->mad_frame_finish(&p->Frame);
p->mad_stream_finish(&p->Stream);
p->mad_stream_init(&p->Stream);
p->mad_frame_init(&p->Frame);
p->mad_synth_init(&p->Synth);
offset /= ft->signal.channels;
to_skip_samples = offset;
while(sox_true) { /* Read data from the MP3 file */
size_t padding = 0;
size_t read;
size_t leftover = p->Stream.bufend - p->Stream.next_frame;
memcpy(p->mp3_buffer, p->Stream.this_frame, leftover);
read = lsx_readbuf(ft, p->mp3_buffer + leftover, p->mp3_buffer_size - leftover);
if (read == 0) {
lsx_debug("seek failure. unexpected EOF (frames=%" PRIuPTR " leftover=%" PRIuPTR ")", p->FrameCount, leftover);
break;
}
for (; !depadded && padding < read && !p->mp3_buffer[padding]; ++padding);
depadded = sox_true;
p->mad_stream_buffer(&p->Stream, p->mp3_buffer + padding, leftover + read - padding);
while (sox_true) { /* Decode frame headers */
static unsigned short samples;
p->Stream.error = MAD_ERROR_NONE;
/* Not an audio frame */
if (p->mad_header_decode(&p->Frame.header, &p->Stream) == -1) {
if (p->Stream.error == MAD_ERROR_BUFLEN)
break; /* Normal behaviour; get some more data from the file */
if (!MAD_RECOVERABLE(p->Stream.error)) {
lsx_warn("unrecoverable MAD error");
break;
}
if (p->Stream.error == MAD_ERROR_LOSTSYNC) {
unsigned available = (p->Stream.bufend - p->Stream.this_frame);
tagsize = tagtype(p->Stream.this_frame, (size_t) available);
if (tagsize) { /* It's some ID3 tags, so just skip */
if (tagsize >= available) {
lsx_seeki(ft, (off_t)(tagsize - available), SEEK_CUR);
depadded = sox_false;
}
p->mad_stream_skip(&p->Stream, min(tagsize, available));
}
else lsx_warn("MAD lost sync");
}
else lsx_warn("recoverable MAD error");
continue;
}
consumed += p->Stream.next_frame - p->Stream.this_frame;
vbr |= (p->Frame.header.bitrate != initial_bitrate);
samples = 32 * MAD_NSBSAMPLES(&p->Frame.header);
p->FrameCount++;
p->mad_timer_add(&p->Timer, p->Frame.header.duration);
if(to_skip_samples <= samples)
{
p->mad_frame_decode(&p->Frame,&p->Stream);
p->mad_synth_frame(&p->Synth, &p->Frame);
p->cursamp = to_skip_samples;
return SOX_SUCCESS;
}
else to_skip_samples -= samples;
/* If not VBR, we can extrapolate frame size */
if (p->FrameCount == 64 && !vbr) {
p->FrameCount = offset / samples;
to_skip_samples = offset % samples;
if (SOX_SUCCESS != lsx_seeki(ft, (off_t)(p->FrameCount * consumed / 64 + tagsize), SEEK_SET))
return SOX_EOF;
/* Reset Stream for refilling buffer */
p->mad_stream_finish(&p->Stream);
p->mad_stream_init(&p->Stream);
break;
}
}
};
return SOX_EOF;
}
sox_format_t * sox_open_read(
char const * path,
sox_signalinfo_t const * signal,
sox_encodinginfo_t const * encoding,
char const * filetype)
{
sox_format_t * ft = lsx_calloc(1, sizeof(*ft));
sox_format_handler_t const * handler;
char const * const io_types[] = {"file", "pipe", "file URL"};
char const * type = "";
size_t input_bufsiz = sox_globals.input_bufsiz?
sox_globals.input_bufsiz : sox_globals.bufsiz;
if (filetype) {
if (!(handler = sox_find_format(filetype, sox_false))) {
lsx_fail("no handler for given file type `%s'", filetype);
goto error;
}
ft->handler = *handler;
}
if (!(ft->handler.flags & SOX_FILE_NOSTDIO)) {
if (!strcmp(path, "-")) { /* Use stdin if the filename is "-" */
if (sox_globals.stdin_in_use_by) {
lsx_fail("`-' (stdin) already in use by `%s'", sox_globals.stdin_in_use_by);
goto error;
}
sox_globals.stdin_in_use_by = "audio input";
SET_BINARY_MODE(stdin);
ft->fp = stdin;
}
else {
ft->fp = xfopen(path, "rb", &ft->io_type);
type = io_types[ft->io_type];
if (ft->fp == NULL) {
lsx_fail("can't open input %s `%s': %s", type, path, strerror(errno));
goto error;
}
}
if (setvbuf (ft->fp, NULL, _IOFBF, sizeof(char) * input_bufsiz)) {
lsx_fail("Can't set read buffer");
goto error;
}
ft->seekable = is_seekable(ft);
}
if (!filetype) {
if (ft->seekable) {
filetype = auto_detect_format(ft, lsx_find_file_extension(path));
lsx_rewind(ft);
}
#ifndef NO_REWIND_PIPE
else if (!(ft->handler.flags & SOX_FILE_NOSTDIO) &&
input_bufsiz >= AUTO_DETECT_SIZE) {
filetype = auto_detect_format(ft, lsx_find_file_extension(path));
rewind_pipe(ft->fp);
ft->tell_off = 0;
}
#endif
if (filetype) {
lsx_report("detected file format type `%s'", filetype);
if (!(handler = sox_find_format(filetype, sox_false))) {
lsx_fail("no handler for detected file type `%s'", filetype);
goto error;
}
}
else {
if (ft->io_type == lsx_io_pipe) {
filetype = "sox"; /* With successful pipe rewind, this isn't useful */
lsx_report("assuming input pipe `%s' has file-type `sox'", path);
}
else if (!(filetype = lsx_find_file_extension(path))) {
lsx_fail("can't determine type of %s `%s'", type, path);
goto error;
}
if (!(handler = sox_find_format(filetype, sox_true))) {
lsx_fail("no handler for file extension `%s'", filetype);
goto error;
}
}
ft->handler = *handler;
if (ft->handler.flags & SOX_FILE_NOSTDIO) {
xfclose(ft->fp, ft->io_type);
ft->fp = NULL;
}
}
if (!ft->handler.startread && !ft->handler.read) {
lsx_fail("file type `%s' isn't readable", filetype);
goto error;
}
ft->mode = 'r';
ft->filetype = lsx_strdup(filetype);
ft->filename = lsx_strdup(path);
if (signal)
ft->signal = *signal;
if (encoding)
ft->encoding = *encoding;
else sox_init_encodinginfo(&ft->encoding);
set_endiannesses(ft);
if ((ft->handler.flags & SOX_FILE_DEVICE) && !(ft->handler.flags & SOX_FILE_PHONY))
lsx_set_signal_defaults(ft);
ft->priv = lsx_calloc(1, ft->handler.priv_size);
/* Read and write starters can change their formats. */
if (ft->handler.startread && (*ft->handler.startread)(ft) != SOX_SUCCESS) {
lsx_fail("can't open input %s `%s': %s", type, ft->filename, ft->sox_errstr);
goto error;
}
/* Fill in some defaults: */
if (sox_precision(ft->encoding.encoding, ft->encoding.bits_per_sample))
ft->signal.precision = sox_precision(ft->encoding.encoding, ft->encoding.bits_per_sample);
if (!(ft->handler.flags & SOX_FILE_PHONY) && !ft->signal.channels)
ft->signal.channels = 1;
if (sox_checkformat(ft) != SOX_SUCCESS) {
lsx_fail("bad input format for %s `%s': %s", type, ft->filename, ft->sox_errstr);
goto error;
}
if (signal) {
if (signal->rate && signal->rate != ft->signal.rate)
lsx_warn("can't set sample rate %g; using %g", signal->rate, ft->signal.rate);
if (signal->channels && signal->channels != ft->signal.channels)
lsx_warn("can't set %u channels; using %u", signal->channels, ft->signal.channels);
}
return ft;
error:
if (ft->fp && ft->fp != stdin)
xfclose(ft->fp, ft->io_type);
free(ft->priv);
free(ft->filename);
free(ft->filetype);
free(ft);
return NULL;
}
static int startread(sox_format_t * ft)
{
priv_t *p = (priv_t *) ft->priv;
size_t ReadSize;
sox_bool ignore_length = ft->signal.length == SOX_IGNORE_LENGTH;
int open_library_result;
LSX_DLLIBRARY_OPEN(
p,
mad_dl,
MAD_FUNC_ENTRIES,
"MAD decoder library",
mad_library_names,
open_library_result);
if (open_library_result)
return SOX_EOF;
p->mp3_buffer_size = sox_globals.bufsiz;
p->mp3_buffer = lsx_malloc(p->mp3_buffer_size);
ft->signal.length = SOX_UNSPEC;
if (ft->seekable) {
#ifdef USING_ID3TAG
read_comments(ft);
lsx_rewind(ft);
if (!ft->signal.length)
#endif
if (!ignore_length)
ft->signal.length = mp3_duration_ms(ft);
}
p->mad_stream_init(&p->Stream);
p->mad_frame_init(&p->Frame);
p->mad_synth_init(&p->Synth);
mad_timer_reset(&p->Timer);
ft->encoding.encoding = SOX_ENCODING_MP3;
/* Decode at least one valid frame to find out the input
* format. The decoded frame will be saved off so that it
* can be processed later.
*/
ReadSize = lsx_readbuf(ft, p->mp3_buffer, p->mp3_buffer_size);
if (ReadSize != p->mp3_buffer_size && lsx_error(ft))
return SOX_EOF;
p->mad_stream_buffer(&p->Stream, p->mp3_buffer, ReadSize);
/* Find a valid frame before starting up. This makes sure
* that we have a valid MP3 and also skips past ID3v2 tags
* at the beginning of the audio file.
*/
p->Stream.error = 0;
while (p->mad_frame_decode(&p->Frame,&p->Stream))
{
/* check whether input buffer needs a refill */
if (p->Stream.error == MAD_ERROR_BUFLEN)
{
if (sox_mp3_input(ft) == SOX_EOF)
return SOX_EOF;
continue;
}
/* Consume any ID3 tags */
sox_mp3_inputtag(ft);
/* FIXME: We should probably detect when we've read
* a bunch of non-ID3 data and still haven't found a
* frame. In that case we can abort early without
* scanning the whole file.
*/
p->Stream.error = 0;
}
if (p->Stream.error)
{
lsx_fail_errno(ft,SOX_EOF,"No valid MP3 frame found");
return SOX_EOF;
}
switch(p->Frame.header.mode)
{
case MAD_MODE_SINGLE_CHANNEL:
case MAD_MODE_DUAL_CHANNEL:
case MAD_MODE_JOINT_STEREO:
case MAD_MODE_STEREO:
ft->signal.channels = MAD_NCHANNELS(&p->Frame.header);
break;
default:
lsx_fail_errno(ft, SOX_EFMT, "Cannot determine number of channels");
return SOX_EOF;
}
p->FrameCount=1;
p->mad_timer_add(&p->Timer,p->Frame.header.duration);
p->mad_synth_frame(&p->Synth,&p->Frame);
ft->signal.precision = MP3_MAD_PRECISION;
ft->signal.rate=p->Synth.pcm.samplerate;
if (ignore_length)
ft->signal.length = SOX_UNSPEC;
else {
ft->signal.length = (uint64_t)(ft->signal.length * .001 * ft->signal.rate + .5);
ft->signal.length *= ft->signal.channels; /* Keep separate from line above! */
}
p->cursamp = 0;
return SOX_SUCCESS;
}
