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gst/mpegaudioparse/gstmpegaudioparse.*: Add support for seeking based on the VBRI seek table. Might make sense to use...

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Original commit message from CVS:
* gst/mpegaudioparse/gstmpegaudioparse.c: (gst_mp3parse_reset),
(gst_mp3parse_handle_first_frame), (mp3parse_time_to_bytepos),
(mp3parse_bytepos_to_time):
* gst/mpegaudioparse/gstmpegaudioparse.h:
Add support for seeking based on the VBRI seek table. Might make
sense to use interpolation in the table later to get hopefully a
bit more accurate values.
This commit is contained in:
Sebastian Dröge 2008-01-14 15:02:13 +00:00
parent 179887388e
commit 7b5d4c287e
3 changed files with 98 additions and 25 deletions

10
ChangeLog
View file

@ -1,3 +1,13 @@
2008-01-14 Sebastian Dröge <slomo@circular-chaos.org>
* gst/mpegaudioparse/gstmpegaudioparse.c: (gst_mp3parse_reset),
(gst_mp3parse_handle_first_frame), (mp3parse_time_to_bytepos),
(mp3parse_bytepos_to_time):
* gst/mpegaudioparse/gstmpegaudioparse.h:
Add support for seeking based on the VBRI seek table. Might make
sense to use interpolation in the table later to get hopefully a
bit more accurate values.
2008-01-14 Wim Taymans <wim.taymans@collabora.co.uk>
* ext/mpeg2dec/gstmpeg2dec.c: (clear_queued), (flush_queued),

111
gst/mpegaudioparse/gstmpegaudioparse.c
View file

@ -278,6 +278,9 @@ gst_mp3parse_reset (GstMPEGAudioParse * mp3parse)
mp3parse->vbri_frames = 0;
mp3parse->vbri_total_time = 0;
mp3parse->vbri_bytes = 0;
mp3parse->vbri_seek_points = 0;
g_free (mp3parse->vbri_seek_table);
mp3parse->vbri_seek_table = NULL;
if (mp3parse->seek_table) {
g_list_foreach (mp3parse->seek_table, (GFunc) g_free, NULL);
@ -852,8 +855,7 @@ gst_mp3parse_handle_first_frame (GstMPEGAudioParse * mp3parse)
} else if (read_id == vbri_id) {
gint64 total_bytes, total_frames;
GstClockTime total_time;
/* guint16 nseek_points; */
guint16 nseek_points;
GST_DEBUG_OBJECT (mp3parse, "Found VBRI header marker 0x%x", vbri_id);
if (avail < offset + 26) {
@ -866,10 +868,8 @@ gst_mp3parse_handle_first_frame (GstMPEGAudioParse * mp3parse)
data = gst_adapter_peek (mp3parse->adapter, offset + 26);
data += offset + 4;
g_print ("0x%x %c\n", *(data - 1), *(data - 1));
if (GST_READ_UINT16_BE (data) != 0x0001) {
GST_DEBUG_OBJECT (mp3parse,
GST_WARNING_OBJECT (mp3parse,
"Unsupported VBRI version 0x%x", GST_READ_UINT16_BE (data));
return;
}
@ -904,41 +904,74 @@ gst_mp3parse_handle_first_frame (GstMPEGAudioParse * mp3parse)
mp3parse->vbri_bitrate -= mp3parse->vbri_bitrate % 1000;
}
/* TODO: Parse seek table and use everywhere.
* See http://groups.google.com/group/alt.music.mp3/browse_thread/thread/4036a2ad8f2ed55d/a528fc7afdf353f6?#a528fc7afdf353f6
*/
#if 0
nseek_points = GST_READ_UINT16_BE (data);
data += 2;
if (GST_READ_UINT32_BE (data) != 0x0102) {
GST_DEBUG_OBJECT (mp3parse, "Unsupported VBRI seek table");
return;
} else if (nseek_points > 0) {
guint stride;
if (nseek_points > 0) {
guint scale, seek_bytes, seek_frames;
gint i;
data += 4;
mp3parse->vbri_seek_points = nseek_points;
stride = GST_READ_UINT16_BE (data);
if (stride == 0) {
GST_DEBUG_OBJECT (mp3parse, "Unsupported VBRI seek table");
return;
scale = GST_READ_UINT16_BE (data);
data += 2;
seek_bytes = GST_READ_UINT16_BE (data);
data += 2;
seek_frames = GST_READ_UINT16_BE (data);
data += 2;
if (scale == 0 || seek_bytes == 0 || seek_bytes == 3 || seek_bytes > 4
|| seek_frames == 0) {
GST_WARNING_OBJECT (mp3parse, "Unsupported VBRI seek table");
goto out_vbri;
}
if (avail < offset + 26 + nseek_points * 2) {
GST_DEBUG_OBJECT (mp3parse,
if (avail < offset + 26 + nseek_points * seek_bytes) {
GST_WARNING_OBJECT (mp3parse,
"Not enough data to read VBRI seek table (need %d)",
offset + 26 + nseek_points * 2);
return;
offset + 26 + nseek_points * seek_bytes);
goto out_vbri;
}
if (seek_frames * nseek_points < total_frames - seek_frames ||
seek_frames * nseek_points > total_frames + seek_frames) {
GST_WARNING_OBJECT (mp3parse,
"VBRI seek table doesn't cover the complete file");
goto out_vbri;
}
data =
gst_adapter_peek (mp3parse->adapter, offset + 26 + nseek_points * 2);
gst_adapter_peek (mp3parse->adapter,
offset + 26 + nseek_points * seek_bytes);
data += offset + 26;
/* VBRI seek table: frame/seek_frames -> byte */
mp3parse->vbri_seek_table = g_new (guint32, nseek_points);
if (seek_bytes == 4)
for (i = 0; i < nseek_points; i++) {
mp3parse->vbri_seek_table[i] =
(i > 0) ? mp3parse->vbri_seek_table[i - 1] : 0;
mp3parse->vbri_seek_table[i] += GST_READ_UINT32_BE (data) * scale;
data += 4;
} else if (seek_bytes == 2)
for (i = 0; i < nseek_points; i++) {
mp3parse->vbri_seek_table[i] =
(i > 0) ? mp3parse->vbri_seek_table[i - 1] : 0;
mp3parse->vbri_seek_table[i] += GST_READ_UINT16_BE (data) * scale;
data += 2;
} else /* seek_bytes == 1 */
for (i = 0; i < nseek_points; i++) {
mp3parse->vbri_seek_table[i] =
(i > 0) ? mp3parse->vbri_seek_table[i - 1] : 0;
mp3parse->vbri_seek_table[i] += GST_READ_UINT8 (data) * scale;
data += 1;
}
}
#endif
out_vbri:
GST_DEBUG_OBJECT (mp3parse, "VBRI header reported %u frames, time %"
GST_TIME_FORMAT ", bytes %u", mp3parse->vbri_frames,
GST_TIME_ARGS (mp3parse->vbri_total_time), mp3parse->vbri_bytes);
@ -1335,6 +1368,18 @@ mp3parse_time_to_bytepos (GstMPEGAudioParse * mp3parse, GstClockTime ts,
return TRUE;
}
if (mp3parse->vbri_seek_table &&
mp3parse_total_bytes (mp3parse, &total_bytes) &&
mp3parse_total_time (mp3parse, &total_time)) {
gint i = gst_util_uint64_scale (ts, mp3parse->vbri_seek_points, total_time);
i = CLAMP (i, 0, mp3parse->vbri_seek_points);
*bytepos = mp3parse->vbri_seek_table[i];
return TRUE;
}
if (mp3parse->avg_bitrate == 0)
goto no_bitrate;
@ -1384,6 +1429,22 @@ mp3parse_bytepos_to_time (GstMPEGAudioParse * mp3parse,
return TRUE;
}
if (mp3parse->vbri_seek_table &&
mp3parse_total_bytes (mp3parse, &total_bytes) &&
mp3parse_total_time (mp3parse, &total_time)) {
gint i = 0;
while (mp3parse->vbri_seek_table[i] < bytepos
&& i < mp3parse->vbri_seek_points)
i++;
i = CLAMP (i, 0, mp3parse->vbri_seek_points);
*ts = gst_util_uint64_scale (total_time, i, mp3parse->vbri_seek_points);
return TRUE;
}
/* Cannot convert anything except 0 if we don't have a bitrate yet */
if (mp3parse->avg_bitrate == 0)
return FALSE;

2
gst/mpegaudioparse/gstmpegaudioparse.h
View file

@ -108,6 +108,8 @@ struct _GstMPEGAudioParse {
GstClockTime vbri_total_time;
guint32 vbri_bytes;
guint vbri_bitrate;
guint vbri_seek_points;
guint32 *vbri_seek_table;
/* Accurate seeking */
GList *seek_table;