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 FFmpeg.
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include "aacadtsdec.h"
27 #include "mpeg4audio.h"
30 typedef struct AACBSFContext {
35 * This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4
36 * ADTS header and removes the ADTS header.
38 static int aac_adtstoasc_filter(AVBSFContext *bsfc, AVPacket *out)
40 AACBSFContext *ctx = bsfc->priv_data;
44 AACADTSHeaderInfo hdr;
48 ret = ff_bsf_get_packet(bsfc, &in);
52 if (bsfc->par_in->extradata && in->size >= 2 && (AV_RB16(in->data) >> 4) != 0xfff)
55 if (in->size < AAC_ADTS_HEADER_SIZE)
56 goto packet_too_small;
58 init_get_bits(&gb, in->data, AAC_ADTS_HEADER_SIZE * 8);
60 if (avpriv_aac_parse_header(&gb, &hdr) < 0) {
61 av_log(bsfc, AV_LOG_ERROR, "Error parsing ADTS frame header!\n");
62 ret = AVERROR_INVALIDDATA;
66 if (!hdr.crc_absent && hdr.num_aac_frames > 1) {
67 avpriv_report_missing_feature(bsfc,
68 "Multiple RDBs per frame with CRC");
69 ret = AVERROR_PATCHWELCOME;
73 in->size -= AAC_ADTS_HEADER_SIZE + 2 * !hdr.crc_absent;
75 goto packet_too_small;
76 in->data += AAC_ADTS_HEADER_SIZE + 2 * !hdr.crc_absent;
78 if (!ctx->first_frame_done) {
80 uint8_t pce_data[MAX_PCE_SIZE];
83 if (!hdr.chan_config) {
84 init_get_bits(&gb, in->data, in->size * 8);
85 if (get_bits(&gb, 3) != 5) {
86 avpriv_report_missing_feature(bsfc,
87 "PCE-based channel configuration "
88 "without PCE as first syntax "
90 ret = AVERROR_PATCHWELCOME;
93 init_put_bits(&pb, pce_data, MAX_PCE_SIZE);
94 pce_size = avpriv_copy_pce_data(&pb, &gb)/8;
96 in->size -= get_bits_count(&gb)/8;
97 in->data += get_bits_count(&gb)/8;
100 extradata = av_packet_new_side_data(in, AV_PKT_DATA_NEW_EXTRADATA,
103 ret = AVERROR(ENOMEM);
107 init_put_bits(&pb, extradata, 2 + pce_size);
108 put_bits(&pb, 5, hdr.object_type);
109 put_bits(&pb, 4, hdr.sampling_index);
110 put_bits(&pb, 4, hdr.chan_config);
111 put_bits(&pb, 1, 0); //frame length - 1024 samples
112 put_bits(&pb, 1, 0); //does not depend on core coder
113 put_bits(&pb, 1, 0); //is not extension
116 memcpy(extradata + 2, pce_data, pce_size);
119 ctx->first_frame_done = 1;
123 av_packet_move_ref(out, in);
129 av_log(bsfc, AV_LOG_ERROR, "Input packet too small\n");
130 ret = AVERROR_INVALIDDATA;
136 static int aac_adtstoasc_init(AVBSFContext *ctx)
138 /* Validate the extradata if the stream is already MPEG-4 AudioSpecificConfig */
139 if (ctx->par_in->extradata) {
140 MPEG4AudioConfig mp4ac;
141 int ret = avpriv_mpeg4audio_get_config(&mp4ac, ctx->par_in->extradata,
142 ctx->par_in->extradata_size * 8, 1);
144 av_log(ctx, AV_LOG_ERROR, "Error parsing AudioSpecificConfig extradata!\n");
152 static const enum AVCodecID codec_ids[] = {
153 AV_CODEC_ID_AAC, AV_CODEC_ID_NONE,
156 const AVBitStreamFilter ff_aac_adtstoasc_bsf = {
157 .name = "aac_adtstoasc",
158 .priv_data_size = sizeof(AACBSFContext),
159 .init = aac_adtstoasc_init,
160 .filter = aac_adtstoasc_filter,
161 .codec_ids = codec_ids,