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aacparse: Fix bitrate calculation

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This patch adds the get_frame_overhead() vfunc so that baseparse can
accurately calculate the min/avg/max bitrates for aacparse.

Note: The bitrate was being incorrectly calculated for ADTS streams
(it's not in the header as the code suggests).
This commit is contained in:
Arun Raghavan 2010-03-25 11:48:46 +00:00 committed by Sebastian Dröge
parent 88c1e42567
commit 599401a7f9
1 changed files with 35 additions and 4 deletions
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39
gst/audioparsers/gstaacparse.c
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@ -97,6 +97,8 @@ gboolean gst_aacparse_convert (GstBaseParse * parse,
gboolean gst_aacparse_is_seekable (GstBaseParse * parse);
gint gst_aacparse_get_frame_overhead (GstBaseParse * parse, GstBuffer * buffer);
gboolean gst_aacparse_event (GstBaseParse * parse, GstEvent * event);
#define _do_init(bla) \
@ -160,6 +162,8 @@ gst_aacparse_class_init (GstAacParseClass * klass)
parse_class->parse_frame = GST_DEBUG_FUNCPTR (gst_aacparse_parse_frame);
parse_class->check_valid_frame =
GST_DEBUG_FUNCPTR (gst_aacparse_check_valid_frame);
parse_class->get_frame_overhead =
GST_DEBUG_FUNCPTR (gst_aacparse_get_frame_overhead);
}
@ -462,14 +466,12 @@ gst_aacparse_detect_stream (GstAacParse * aacparse,
aacparse->mpegversion = (data[1] & 0x08) ? 2 : 4;
aacparse->object_type = (data[2] & 0xc0) >> 6;
aacparse->channels = ((data[2] & 0x01) << 2) | ((data[3] & 0xc0) >> 6);
aacparse->bitrate = ((data[5] & 0x1f) << 6) | ((data[6] & 0xfc) >> 2);
gst_base_parse_set_frame_props (GST_BASE_PARSE (aacparse),
aacparse->sample_rate, 1024, 50);
GST_DEBUG ("ADTS: samplerate %d, channels %d, bitrate %d, objtype %d",
aacparse->sample_rate, aacparse->channels, aacparse->bitrate,
aacparse->object_type);
GST_DEBUG ("ADTS: samplerate %d, channels %d, objtype %d",
aacparse->sample_rate, aacparse->channels, aacparse->object_type);
return TRUE;
} else if (need_data) {
@ -706,3 +708,32 @@ gst_aacparse_is_seekable (GstBaseParse * parse)
/* Not seekable if ADIF header is found */
return (aacparse->header_type != DSPAAC_HEADER_ADIF);
}
/**
* gst_aacparse_get_frame_overhead:
* @parse: #GstBaseParse.
* @buffer: #GstBuffer.
*
* Implementation of "get_frame_overhead" vmethod in #GstBaseParse class. ADTS
* streams have a 7 byte header in each frame. MP4 and ADIF streams don't have
* a per-frame header.
*
* We're making a couple of simplifying assumptions:
*
* 1. We count Program Configuration Elements rather than searching for them
* in the streams to discount them - the overhead is negligible.
*
* 2. We ignore CRC. This has a worst-case impact of (num_raw_blocks + 1)*16
* bits, which should still not be significant enough to warrant the
* additional parsing through the headers
*/
gint
gst_aacparse_get_frame_overhead (GstBaseParse * parse, GstBuffer * buffer)
{
GstAacParse *aacparse = GST_AACPARSE (parse);
if (aacparse->header_type == DSPAAC_HEADER_ADTS)
return 7;
else
return 0;
}