2 * MPEG-2/4 AAC ADTS to MPEG-4 Audio Specific Configuration bitstream filter
3 * Copyright (c) 2009 Alex Converse <alex.converse@gmail.com>
5 * This file is part of Libav.
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "adts_header.h"
23 #include "adts_parser.h"
28 #include "mpeg4audio.h"
31 typedef struct AACBSFContext {
36 * This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4
37 * ADTS header and removes the ADTS header.
39 static int aac_adtstoasc_filter(AVBSFContext *bsfc, AVPacket *out)
41 AACBSFContext *ctx = bsfc->priv_data;
45 AACADTSHeaderInfo hdr;
49 ret = ff_bsf_get_packet(bsfc, &in);
53 if (in->size < AV_AAC_ADTS_HEADER_SIZE)
54 goto packet_too_small;
56 init_get_bits(&gb, in->data, AV_AAC_ADTS_HEADER_SIZE * 8);
58 if (bsfc->par_in->extradata && show_bits(&gb, 12) != 0xfff)
61 if (ff_adts_header_parse(&gb, &hdr) < 0) {
62 av_log(bsfc, AV_LOG_ERROR, "Error parsing ADTS frame header!\n");
63 ret = AVERROR_INVALIDDATA;
67 if (!hdr.crc_absent && hdr.num_aac_frames > 1) {
68 avpriv_report_missing_feature(bsfc,
69 "Multiple RDBs per frame with CRC");
70 ret = AVERROR_PATCHWELCOME;
74 in->size -= AV_AAC_ADTS_HEADER_SIZE + 2 * !hdr.crc_absent;
76 goto packet_too_small;
77 in->data += AV_AAC_ADTS_HEADER_SIZE + 2 * !hdr.crc_absent;
79 if (!ctx->first_frame_done) {
81 uint8_t pce_data[MAX_PCE_SIZE];
84 if (!hdr.chan_config) {
85 init_get_bits(&gb, in->data, in->size * 8);
86 if (get_bits(&gb, 3) != 5) {
87 avpriv_report_missing_feature(bsfc,
88 "PCE-based channel configuration "
89 "without PCE as first syntax "
91 ret = AVERROR_PATCHWELCOME;
94 init_put_bits(&pb, pce_data, MAX_PCE_SIZE);
95 pce_size = ff_copy_pce_data(&pb, &gb) / 8;
97 in->size -= get_bits_count(&gb)/8;
98 in->data += get_bits_count(&gb)/8;
101 extradata = av_packet_new_side_data(in, AV_PKT_DATA_NEW_EXTRADATA,
104 ret = AVERROR(ENOMEM);
108 init_put_bits(&pb, extradata, 2 + pce_size);
109 put_bits(&pb, 5, hdr.object_type);
110 put_bits(&pb, 4, hdr.sampling_index);
111 put_bits(&pb, 4, hdr.chan_config);
112 put_bits(&pb, 1, 0); //frame length - 1024 samples
113 put_bits(&pb, 1, 0); //does not depend on core coder
114 put_bits(&pb, 1, 0); //is not extension
117 memcpy(extradata + 2, pce_data, pce_size);
120 ctx->first_frame_done = 1;
124 av_packet_move_ref(out, in);
130 av_log(bsfc, AV_LOG_ERROR, "Input packet too small\n");
131 ret = AVERROR_INVALIDDATA;
137 static int aac_adtstoasc_init(AVBSFContext *ctx)
139 /* Validate the extradata if the stream is already MPEG-4 AudioSpecificConfig */
140 if (ctx->par_in->extradata) {
141 MPEG4AudioConfig mp4ac;
142 int ret = avpriv_mpeg4audio_get_config(&mp4ac, ctx->par_in->extradata,
143 ctx->par_in->extradata_size * 8, 1);
145 av_log(ctx, AV_LOG_ERROR, "Error parsing AudioSpecificConfig extradata!\n");
153 static const enum AVCodecID codec_ids[] = {
154 AV_CODEC_ID_AAC, AV_CODEC_ID_NONE,
157 const AVBitStreamFilter ff_aac_adtstoasc_bsf = {
158 .name = "aac_adtstoasc",
159 .priv_data_size = sizeof(AACBSFContext),
160 .init = aac_adtstoasc_init,
161 .filter = aac_adtstoasc_filter,
162 .codec_ids = codec_ids,