ref: 63010290b20efc4ecbafc98ff34a937bdb40524b
dir: /src/mp3-util.h/
/* libSoX MP3 utilities Copyright (c) 2007-9 SoX contributors
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at
* your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <sys/stat.h>
#if defined(HAVE_LAME)
static void write_comments(sox_format_t * ft)
{
priv_t *p = (priv_t *) ft->priv;
const char* comment;
p->id3tag_init(p->gfp);
p->id3tag_set_pad(p->gfp, (size_t)ID3PADDING);
/* Note: id3tag_set_fieldvalue is not present in LAME 3.97, so we're using
the 3.97-compatible methods for all of the tags that 3.97 supported. */
/* FIXME: This is no more necessary, since support for LAME 3.97 has ended. */
if ((comment = sox_find_comment(ft->oob.comments, "Title")))
p->id3tag_set_title(p->gfp, comment);
if ((comment = sox_find_comment(ft->oob.comments, "Artist")))
p->id3tag_set_artist(p->gfp, comment);
if ((comment = sox_find_comment(ft->oob.comments, "Album")))
p->id3tag_set_album(p->gfp, comment);
if ((comment = sox_find_comment(ft->oob.comments, "Tracknumber")))
p->id3tag_set_track(p->gfp, comment);
if ((comment = sox_find_comment(ft->oob.comments, "Year")))
p->id3tag_set_year(p->gfp, comment);
if ((comment = sox_find_comment(ft->oob.comments, "Comment")))
p->id3tag_set_comment(p->gfp, comment);
if ((comment = sox_find_comment(ft->oob.comments, "Genre")))
{
if (p->id3tag_set_genre(p->gfp, comment))
lsx_warn("\"%s\" is not a recognized ID3v1 genre.", comment);
}
if ((comment = sox_find_comment(ft->oob.comments, "Discnumber")))
{
char* id3tag_buf = lsx_malloc(strlen(comment) + 6);
if (id3tag_buf)
{
sprintf(id3tag_buf, "TPOS=%s", comment);
p->id3tag_set_fieldvalue(p->gfp, id3tag_buf);
free(id3tag_buf);
}
}
}
#endif /* HAVE_LAME */
#ifdef HAVE_MAD_H
static unsigned long xing_frames(priv_t * p, struct mad_bitptr ptr, unsigned bitlen)
{
#define XING_MAGIC ( ('X' << 24) | ('i' << 16) | ('n' << 8) | 'g' )
if (bitlen >= 96 && p->mad_bit_read(&ptr, 32) == XING_MAGIC &&
(p->mad_bit_read(&ptr, 32) & 1 )) /* XING_FRAMES */
return p->mad_bit_read(&ptr, 32);
return 0;
}
static size_t mp3_duration(sox_format_t * ft)
{
priv_t * p = (priv_t *) ft->priv;
struct mad_stream mad_stream;
struct mad_header mad_header;
struct mad_frame mad_frame;
size_t initial_bitrate = 0; /* Initialised to prevent warning */
size_t tagsize = 0, consumed = 0, frames = 0;
sox_bool vbr = sox_false, depadded = sox_false;
size_t num_samples = 0;
p->mad_stream_init(&mad_stream);
p->mad_header_init(&mad_header);
p->mad_frame_init(&mad_frame);
do { /* Read data from the MP3 file */
int read, padding = 0;
size_t leftover = mad_stream.bufend - mad_stream.next_frame;
memmove(p->mp3_buffer, mad_stream.this_frame, leftover);
read = lsx_readbuf(ft, p->mp3_buffer + leftover, p->mp3_buffer_size - leftover);
if (read <= 0) {
lsx_debug("got exact duration by scan to EOF (frames=%" PRIuPTR " leftover=%" PRIuPTR ")", frames, leftover);
break;
}
for (; !depadded && padding < read && !p->mp3_buffer[padding]; ++padding);
depadded = sox_true;
p->mad_stream_buffer(&mad_stream, p->mp3_buffer + padding, leftover + read - padding);
while (sox_true) { /* Decode frame headers */
mad_stream.error = MAD_ERROR_NONE;
if (p->mad_header_decode(&mad_header, &mad_stream) == -1) {
if (mad_stream.error == MAD_ERROR_BUFLEN)
break; /* Normal behaviour; get some more data from the file */
if (!MAD_RECOVERABLE(mad_stream.error)) {
lsx_warn("unrecoverable MAD error");
break;
}
if (mad_stream.error == MAD_ERROR_LOSTSYNC) {
unsigned available = (mad_stream.bufend - mad_stream.this_frame);
tagsize = tagtype(mad_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(&mad_stream, min(tagsize, available));
}
else lsx_warn("MAD lost sync");
}
else lsx_warn("recoverable MAD error");
continue; /* Not an audio frame */
}
num_samples += MAD_NSBSAMPLES(&mad_header) * 32;
consumed += mad_stream.next_frame - mad_stream.this_frame;
lsx_debug_more("bitrate=%lu", mad_header.bitrate);
if (!frames) {
initial_bitrate = mad_header.bitrate;
/* Get the precise frame count from the XING header if present */
mad_frame.header = mad_header;
if (p->mad_frame_decode(&mad_frame, &mad_stream) == -1)
if (!MAD_RECOVERABLE(mad_stream.error)) {
lsx_warn("unrecoverable MAD error");
break;
}
if ((frames = xing_frames(p, mad_stream.anc_ptr, mad_stream.anc_bitlen))) {
num_samples *= frames;
lsx_debug("got exact duration from XING frame count (%" PRIuPTR ")", frames);
break;
}
}
else vbr |= mad_header.bitrate != initial_bitrate;
/* If not VBR, we can time just a few frames then extrapolate */
if (++frames == 25 && !vbr) {
double frame_size = (double) consumed / frames;
size_t num_frames = (lsx_filelength(ft) - tagsize) / frame_size;
num_samples = num_samples / frames * num_frames;
lsx_debug("got approx. duration by CBR extrapolation");
break;
}
}
} while (mad_stream.error == MAD_ERROR_BUFLEN);
p->mad_frame_finish(&mad_frame);
mad_header_finish(&mad_header);
p->mad_stream_finish(&mad_stream);
lsx_rewind(ft);
return num_samples;
}
#endif /* HAVE_MAD_H */