gstreamer/gst/mpegtsmux/gstbasetsmuxaac.c
Jan Schmidt 46cc64e09f mpegtsmux: Fix handling of MPEG-2 AAC
The audio/mpeg,mpegversion=2 caps in GStreamer refer to
MPEG-2 AAC (ISO 13818-7), not to the extended MP3 (ISO 13818-3),
which is audio/mpeg,mpegversion=1,mpegaudioversion=2/3

Fix the caps, and add handling for MPEG-2 AAC in both ADTS and raw
form, adding ADTS headers for the latter.
2020-07-08 12:24:13 +00:00

263 lines
9.2 KiB
C

/*
* Copyright 2006, 2007, 2008 Fluendo S.A.
* Authors: Jan Schmidt <jan@fluendo.com>
* Kapil Agrawal <kapil@fluendo.com>
* Julien Moutte <julien@fluendo.com>
*
* This library is licensed under 4 different licenses and you
* can choose to use it under the terms of any one of them. The
* four licenses are the MPL 1.1, the LGPL, the GPL and the MIT
* license.
*
* MPL:
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
* License for the specific language governing rights and limitations
* under the License.
*
* LGPL:
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
* GPL:
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
*
* MIT:
*
* Unless otherwise indicated, Source Code is licensed under MIT license.
* See further explanation attached in License Statement (distributed in the file
* LICENSE).
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
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* of the Software, and to permit persons to whom the Software is furnished to do
* so, subject to the following conditions:
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* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/pbutils/pbutils.h>
#include "gstbasetsmuxaac.h"
#include <string.h>
#define GST_CAT_DEFAULT gst_base_ts_mux_debug
static GstBuffer *
gst_base_ts_mux_prepare_aac_adts (GstBuffer * buf,
GstBaseTsMux * mux, gboolean is_mpeg2, guint8 obj_type_profile,
guint8 rate_idx, guint8 channels)
{
guint8 adts_header[7] = { 0, };
gsize out_size = gst_buffer_get_size (buf) + 7;
GstBuffer *out_buf = gst_buffer_new_and_alloc (out_size);
gsize out_offset = 0;
GstMapInfo buf_map;
/* Generate ADTS header */
GST_DEBUG_OBJECT (mux, "Preparing AAC buffer for output");
gst_buffer_copy_into (out_buf, buf,
GST_BUFFER_COPY_METADATA | GST_BUFFER_COPY_TIMESTAMPS, 0, 0);
GST_DEBUG_OBJECT (mux, "Rate index %u, channels %u, object type/profile %u",
rate_idx, channels, obj_type_profile);
/* Sync point over a full byte */
adts_header[0] = 0xFF;
/* Sync point continued over first 4 bits + static 4 bits
* (ID, layer, protection)*/
adts_header[1] = 0xF1 | (is_mpeg2 ? 0x8 : 0x0);
/* Object type (MPEG4) / Profile (MPEG2) over first 2 bits */
adts_header[2] = (obj_type_profile - 1) << 6;
/* rate index over next 4 bits */
adts_header[2] |= (rate_idx << 2);
/* channels over last 2 bits */
adts_header[2] |= (channels & 0x4) >> 2;
/* channels continued over next 2 bits + 4 bits at zero */
adts_header[3] = (channels & 0x3) << 6;
/* frame size over last 2 bits */
adts_header[3] |= (out_size & 0x1800) >> 11;
/* frame size continued over full byte */
adts_header[4] = (out_size & 0x1FF8) >> 3;
/* frame size continued first 3 bits */
adts_header[5] = (out_size & 0x7) << 5;
/* buffer fullness (0x7FF for VBR) over 5 last bits */
adts_header[5] |= 0x1F;
/* buffer fullness (0x7FF for VBR) continued over 6 first bits + 2 zeros for
* number of raw data blocks */
adts_header[6] = 0xFC;
/* Insert ADTS header */
gst_buffer_fill (out_buf, out_offset, adts_header, 7);
out_offset += 7;
gst_buffer_map (buf, &buf_map, GST_MAP_READ);
/* Now copy complete frame */
gst_buffer_fill (out_buf, out_offset, buf_map.data, buf_map.size);
gst_buffer_unmap (buf, &buf_map);
return out_buf;
}
/* Constructs a dummy codec_data buffer for generating ADTS headers
* from raw MPEG-2 AAC input, where we don't expect codec_data in the caps,
* and need to get the info from the profile/channels/rate fields */
GstBuffer *
gst_base_ts_mux_aac_mpeg2_make_codec_data (GstBaseTsMux * mux,
const GstCaps * caps)
{
const GstStructure *s;
const gchar *profile_str;
gint channels, rate;
guint8 profile_idx, channel_idx;
gint rate_idx;
GstMapInfo map;
GstBuffer *ret;
s = gst_caps_get_structure (caps, 0);
profile_str = gst_structure_get_string (s, "profile");
if (G_UNLIKELY (profile_str == NULL)) {
GST_ERROR_OBJECT (mux, "AAC caps do not contain profile");
return NULL;
}
if (G_UNLIKELY (!gst_structure_get_int (s, "rate", &rate))) {
GST_ERROR_OBJECT (mux, "AAC caps do not contain a sample rate");
return NULL;
}
if (G_UNLIKELY (!gst_structure_get_int (s, "channels", &channels))) {
GST_ERROR_OBJECT (mux, "AAC caps do not contain channel count");
return NULL;
}
if (g_strcmp0 (profile_str, "main") == 0) {
profile_idx = (guint8) 0U;
} else if (g_strcmp0 (profile_str, "lc") == 0) {
profile_idx = (guint8) 1U;
} else if (g_strcmp0 (profile_str, "ssr") == 0) {
profile_idx = (guint8) 2U;
} else {
GST_ERROR_OBJECT (mux, "Invalid profile %s for MPEG-2 AAC caps",
profile_str);
return NULL;
}
if (channels >= 1 && channels <= 6) /* Mono up to & including 5.1 */
channel_idx = (guint8) channels;
else if (channels == 8) /* 7.1 */
channel_idx = (guint8) 7U;
else {
GST_ERROR_OBJECT (mux, "Invalid channel count %d for MPEG-2 AAC caps",
channels);
return NULL;
}
rate_idx = gst_codec_utils_aac_get_index_from_sample_rate (rate);
if (rate_idx < 0) {
GST_ERROR_OBJECT (mux, "Invalid samplerate %d for MPEG-2 AAC caps", rate);
return NULL;
}
ret = gst_buffer_new_and_alloc (3);
gst_buffer_map (ret, &map, GST_MAP_READ);
map.data[0] = profile_idx;
map.data[1] = (guint8) rate_idx;
map.data[2] = channel_idx;
gst_buffer_unmap (ret, &map);
return ret;
}
GstBuffer *
gst_base_ts_mux_prepare_aac_mpeg4 (GstBuffer * buf, GstBaseTsMuxPad * pad,
GstBaseTsMux * mux)
{
GstMapInfo codec_data_map;
guint8 rate_idx = 0, channels = 0, obj_type = 0;
g_return_val_if_fail (pad->codec_data != NULL, NULL);
gst_buffer_map (pad->codec_data, &codec_data_map, GST_MAP_READ);
obj_type = GST_READ_UINT8 (codec_data_map.data) >> 3;
rate_idx = (GST_READ_UINT8 (codec_data_map.data) & 0x7) << 1;
rate_idx |= (GST_READ_UINT8 (codec_data_map.data + 1) & 0x80) >> 7;
channels = (GST_READ_UINT8 (codec_data_map.data + 1) & 0x78) >> 3;
gst_buffer_unmap (pad->codec_data, &codec_data_map);
return gst_base_ts_mux_prepare_aac_adts (buf, mux, FALSE, obj_type, rate_idx,
channels);
}
GstBuffer *
gst_base_ts_mux_prepare_aac_mpeg2 (GstBuffer * buf, GstBaseTsMuxPad * pad,
GstBaseTsMux * mux)
{
GstMapInfo codec_data_map;
guint8 rate_idx = 0, channels = 0, profile_obj_type = 0;
g_return_val_if_fail (pad->codec_data != NULL, NULL);
/* Dummy codec data with 3 bytes of profile_idx, rate_idx, channel_idx */
gst_buffer_map (pad->codec_data, &codec_data_map, GST_MAP_READ);
profile_obj_type = GST_READ_UINT8 (codec_data_map.data);
rate_idx = GST_READ_UINT8 (codec_data_map.data + 1);
channels = GST_READ_UINT8 (codec_data_map.data + 2);
gst_buffer_unmap (pad->codec_data, &codec_data_map);
return gst_base_ts_mux_prepare_aac_adts (buf, mux, TRUE, profile_obj_type,
rate_idx, channels);
}