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185 lines
5.6 KiB
185 lines
5.6 KiB
/** |
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* RTP Depacketization of MP4A-LATM, RFC 3016 |
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* Copyright (c) 2010 Martin Storsjo |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#include "rtpdec_formats.h" |
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#include "internal.h" |
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#include "libavutil/avstring.h" |
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#include "libavcodec/get_bits.h" |
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struct PayloadContext { |
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AVIOContext *dyn_buf; |
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uint8_t *buf; |
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int pos, len; |
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uint32_t timestamp; |
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}; |
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static PayloadContext *latm_new_context(void) |
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{ |
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return av_mallocz(sizeof(PayloadContext)); |
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} |
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static void latm_free_context(PayloadContext *data) |
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{ |
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if (!data) |
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return; |
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if (data->dyn_buf) { |
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uint8_t *p; |
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avio_close_dyn_buf(data->dyn_buf, &p); |
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av_free(p); |
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} |
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av_free(data->buf); |
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av_free(data); |
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} |
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static int latm_parse_packet(AVFormatContext *ctx, PayloadContext *data, |
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AVStream *st, AVPacket *pkt, uint32_t *timestamp, |
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const uint8_t *buf, int len, int flags) |
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{ |
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int ret, cur_len; |
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if (buf) { |
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if (!data->dyn_buf || data->timestamp != *timestamp) { |
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av_freep(&data->buf); |
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if (data->dyn_buf) |
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avio_close_dyn_buf(data->dyn_buf, &data->buf); |
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data->dyn_buf = NULL; |
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av_freep(&data->buf); |
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data->timestamp = *timestamp; |
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if ((ret = avio_open_dyn_buf(&data->dyn_buf)) < 0) |
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return ret; |
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} |
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avio_write(data->dyn_buf, buf, len); |
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if (!(flags & RTP_FLAG_MARKER)) |
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return AVERROR(EAGAIN); |
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av_free(data->buf); |
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data->len = avio_close_dyn_buf(data->dyn_buf, &data->buf); |
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data->dyn_buf = NULL; |
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data->pos = 0; |
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} |
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if (!data->buf) { |
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av_log(ctx, AV_LOG_ERROR, "No data available yet\n"); |
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return AVERROR(EIO); |
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} |
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cur_len = 0; |
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while (data->pos < data->len) { |
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uint8_t val = data->buf[data->pos++]; |
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cur_len += val; |
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if (val != 0xff) |
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break; |
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} |
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if (data->pos + cur_len > data->len) { |
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av_log(ctx, AV_LOG_ERROR, "Malformed LATM packet\n"); |
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return AVERROR(EIO); |
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} |
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if ((ret = av_new_packet(pkt, cur_len)) < 0) |
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return ret; |
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memcpy(pkt->data, data->buf + data->pos, cur_len); |
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data->pos += cur_len; |
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pkt->stream_index = st->index; |
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return data->pos < data->len; |
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} |
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static int parse_fmtp_config(AVStream *st, char *value) |
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{ |
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int len = ff_hex_to_data(NULL, value), i, ret = 0; |
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GetBitContext gb; |
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uint8_t *config; |
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int audio_mux_version, same_time_framing, num_programs, num_layers; |
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/* Pad this buffer, too, to avoid out of bounds reads with get_bits below */ |
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config = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE); |
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if (!config) |
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return AVERROR(ENOMEM); |
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ff_hex_to_data(config, value); |
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init_get_bits(&gb, config, len*8); |
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audio_mux_version = get_bits(&gb, 1); |
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same_time_framing = get_bits(&gb, 1); |
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skip_bits(&gb, 6); /* num_sub_frames */ |
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num_programs = get_bits(&gb, 4); |
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num_layers = get_bits(&gb, 3); |
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if (audio_mux_version != 0 || same_time_framing != 1 || num_programs != 0 || |
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num_layers != 0) { |
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av_log(NULL, AV_LOG_WARNING, "Unsupported LATM config (%d,%d,%d,%d)\n", |
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audio_mux_version, same_time_framing, |
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num_programs, num_layers); |
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ret = AVERROR_PATCHWELCOME; |
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goto end; |
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} |
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av_freep(&st->codec->extradata); |
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st->codec->extradata_size = (get_bits_left(&gb) + 7)/8; |
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st->codec->extradata = av_mallocz(st->codec->extradata_size + |
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FF_INPUT_BUFFER_PADDING_SIZE); |
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if (!st->codec->extradata) { |
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ret = AVERROR(ENOMEM); |
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goto end; |
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} |
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for (i = 0; i < st->codec->extradata_size; i++) |
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st->codec->extradata[i] = get_bits(&gb, 8); |
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end: |
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av_free(config); |
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return ret; |
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} |
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static int parse_fmtp(AVStream *stream, PayloadContext *data, |
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char *attr, char *value) |
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{ |
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int res; |
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if (!strcmp(attr, "config")) { |
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res = parse_fmtp_config(stream, value); |
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if (res < 0) |
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return res; |
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} else if (!strcmp(attr, "cpresent")) { |
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int cpresent = atoi(value); |
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if (cpresent != 0) |
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av_log_missing_feature(NULL, "RTP MP4A-LATM with in-band " |
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"configuration", 1); |
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} |
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return 0; |
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} |
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static int latm_parse_sdp_line(AVFormatContext *s, int st_index, |
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PayloadContext *data, const char *line) |
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{ |
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const char *p; |
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if (av_strstart(line, "fmtp:", &p)) |
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return ff_parse_fmtp(s->streams[st_index], data, p, parse_fmtp); |
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return 0; |
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} |
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RTPDynamicProtocolHandler ff_mp4a_latm_dynamic_handler = { |
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.enc_name = "MP4A-LATM", |
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.codec_type = AVMEDIA_TYPE_AUDIO, |
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.codec_id = CODEC_ID_AAC, |
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.parse_sdp_a_line = latm_parse_sdp_line, |
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.alloc = latm_new_context, |
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.free = latm_free_context, |
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.parse_packet = latm_parse_packet |
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};
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