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aacparse: parse GASpecificConfig for channels

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Some media have valid channel information in GASpecificConfig which is
not yet implemented in gstaacparse. Parse data according to ISO/IEC
14496-3 just enough to get channels.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4720>
This commit is contained in:
Hyung Song 2023-05-18 10:25:44 +09:00 committed by GStreamer Marge Bot
parent 0fd3c28620
commit d68a7fbd94
1 changed files with 90 additions and 2 deletions
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92
subprojects/gst-plugins-good/gst/audioparsers/gstaacparse.c
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@ -544,6 +544,70 @@ gst_aac_parse_get_audio_sample_rate (GstAacParse * aacparse, GstBitReader * br,
return TRUE;
}
static gboolean
gst_aac_parse_program_config_element (GstAacParse * aacparse,
GstBitReader * br, gint * channels)
{
guint8 G_GNUC_UNUSED element_instance_tag;
guint8 G_GNUC_UNUSED object_type;
guint8 G_GNUC_UNUSED sampling_frequency_index;
guint8 num_front_channel_elements;
guint8 num_side_channel_elements;
guint8 num_back_channel_elements;
guint8 num_lfe_channel_elements;
if (!gst_bit_reader_get_bits_uint8 (br, &element_instance_tag, 4))
return FALSE;
if (!gst_bit_reader_get_bits_uint8 (br, &object_type, 2))
return FALSE;
if (!gst_bit_reader_get_bits_uint8 (br, &sampling_frequency_index, 4))
return FALSE;
if (!gst_bit_reader_get_bits_uint8 (br, &num_front_channel_elements, 4))
return FALSE;
if (!gst_bit_reader_get_bits_uint8 (br, &num_side_channel_elements, 4))
return FALSE;
if (!gst_bit_reader_get_bits_uint8 (br, &num_back_channel_elements, 4))
return FALSE;
if (!gst_bit_reader_get_bits_uint8 (br, &num_lfe_channel_elements, 4))
return FALSE;
GST_LOG_OBJECT (aacparse, "channels front %d side %d back %d lfe %d ",
num_front_channel_elements, num_side_channel_elements,
num_back_channel_elements, num_lfe_channel_elements);
*channels = num_front_channel_elements + num_side_channel_elements +
num_back_channel_elements + num_lfe_channel_elements;
return TRUE;
}
static gboolean
gst_aac_parse_ga_specific_config (GstAacParse * aacparse,
GstBitReader * br, gint * channels, guint8 channel_configuration)
{
guint8 G_GNUC_UNUSED frame_length_flag;
guint8 depends_on_core_coder;
guint32 G_GNUC_UNUSED core_coder_delay;
guint8 G_GNUC_UNUSED extension_flag;
if (!gst_bit_reader_get_bits_uint8 (br, &frame_length_flag, 1))
return FALSE;
if (!gst_bit_reader_get_bits_uint8 (br, &depends_on_core_coder, 1))
return FALSE;
if (depends_on_core_coder) {
if (!gst_bit_reader_get_bits_uint32 (br, &core_coder_delay, 14))
return FALSE;
}
if (!gst_bit_reader_get_bits_uint8 (br, &extension_flag, 1))
return FALSE;
if (!channel_configuration) {
return gst_aac_parse_program_config_element (aacparse, br, channels);
}
return TRUE;
}
/* See table 1.13 in ISO/IEC 14496-3 */
static gboolean
gst_aac_parse_read_audio_specific_config (GstAacParse * aacparse,
@ -567,8 +631,6 @@ gst_aac_parse_read_audio_specific_config (GstAacParse * aacparse,
return FALSE;
*channels = loas_channels_table[channel_configuration];
GST_LOG_OBJECT (aacparse, "channel_configuration: %d", channel_configuration);
if (!*channels)
return FALSE;
if (audio_object_type == 5 || audio_object_type == 29) {
extension_audio_object_type = 5;
@ -618,6 +680,32 @@ gst_aac_parse_read_audio_specific_config (GstAacParse * aacparse,
*frame_samples = frame_flag ? 960 : 1024;
}
switch (audio_object_type) {
case 1:
case 2:
case 3:
case 4:
case 6:
case 7:
case 17:
case 19:
case 20:
case 21:
case 22:
case 23:
if (!gst_aac_parse_ga_specific_config (aacparse, br, channels,
channel_configuration)) {
GST_WARNING_OBJECT (aacparse, "Error parsing GASpecificConfig");
return FALSE;
}
break;
default:
break;
}
if (!*channels)
return FALSE;
/* There's LOTS of stuff next, but we ignore it for now as we have
what we want (sample rate and number of channels */
GST_DEBUG_OBJECT (aacparse,