From 96084251e57d1738fde02a2b0d37ca609d9efd71 Mon Sep 17 00:00:00 2001 From: Gilles Chanteperdrix Date: Fri, 13 Feb 2015 22:51:33 +0100 Subject: libavformat: add robust MPEG audio depacketization (RFC 5219) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Martin Storsjö --- libavformat/rtpdec_mpa_robust.c | 224 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 224 insertions(+) create mode 100644 libavformat/rtpdec_mpa_robust.c (limited to 'libavformat/rtpdec_mpa_robust.c') diff --git a/libavformat/rtpdec_mpa_robust.c b/libavformat/rtpdec_mpa_robust.c new file mode 100644 index 0000000000..b3eda3850e --- /dev/null +++ b/libavformat/rtpdec_mpa_robust.c @@ -0,0 +1,224 @@ +/* + * RTP parser for loss tolerant payload format for MP3 audio (RFC 5219) + * Copyright (c) 2015 Gilles Chanteperdrix + * + * This file is part of Libav. + * + * Libav is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * Libav 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "libavutil/attributes.h" +#include "libavutil/intreadwrite.h" + +#include "rtpdec_formats.h" + +struct PayloadContext { + unsigned adu_size; + unsigned cur_size; + uint32_t timestamp; + uint8_t *split_buf; + int split_pos, split_buf_size, split_pkts; + AVIOContext *fragment; +}; + +static av_cold int mpa_robust_init(AVFormatContext *ctx, int st_index, + PayloadContext *data) +{ + if (st_index < 0) + return 0; + ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_HEADERS; + return 0; +} + +static PayloadContext *mpa_robust_new_context(void) +{ + return av_mallocz(sizeof(PayloadContext)); +} + +static inline void free_fragment(PayloadContext *data) +{ + if (data->fragment) { + uint8_t *p; + avio_close_dyn_buf(data->fragment, &p); + av_free(p); + data->fragment = NULL; + } +} + +static void mpa_robust_free_context(PayloadContext *data) +{ + free_fragment(data); + av_free(data->split_buf); + av_free(data); +} + +static int mpa_robust_parse_rtp_header(AVFormatContext *ctx, + const uint8_t *buf, int len, + unsigned *adu_size, unsigned *cont) +{ + unsigned header_size; + + if (len < 2) { + av_log(ctx, AV_LOG_ERROR, "Invalid %d bytes packet\n", len); + return AVERROR_INVALIDDATA; + } + + *cont = !!(buf[0] & 0x80); + if (!(buf[0] & 0x40)) { + header_size = 1; + *adu_size = buf[0] & ~0xc0; + } else { + header_size = 2; + *adu_size = AV_RB16(buf) & ~0xc000; + } + + return header_size; +} + +static int mpa_robust_parse_packet(AVFormatContext *ctx, PayloadContext *data, + AVStream *st, AVPacket *pkt, + uint32_t *timestamp, const uint8_t *buf, + int len, uint16_t seq, int flags) +{ + unsigned adu_size, continuation; + int err, header_size; + + if (!buf) { + buf = &data->split_buf[data->split_pos]; + len = data->split_buf_size - data->split_pos; + + header_size = mpa_robust_parse_rtp_header(ctx, buf, len, &adu_size, + &continuation); + if (header_size < 0) { + av_freep(&data->split_buf); + return header_size; + } + buf += header_size; + len -= header_size; + + if (continuation || adu_size > len) { + av_freep(&data->split_buf); + av_log(ctx, AV_LOG_ERROR, "Invalid frame\n"); + return AVERROR_INVALIDDATA; + } + + if (av_new_packet(pkt, adu_size)) { + av_log(ctx, AV_LOG_ERROR, "Out of memory.\n"); + return AVERROR(ENOMEM); + } + + pkt->stream_index = st->index; + memcpy(pkt->data, buf, adu_size); + + data->split_pos += adu_size; + + if (data->split_pos == data->split_buf_size) { + av_freep(&data->split_buf); + return 0; + } + + return 1; + } + + + header_size = mpa_robust_parse_rtp_header(ctx, buf, len, &adu_size, + &continuation); + if (header_size < 0) + return header_size; + + buf += header_size; + len -= header_size; + + if (!continuation && adu_size <= len) { + /* One or more complete frames */ + + if (av_new_packet(pkt, adu_size)) { + av_log(ctx, AV_LOG_ERROR, "Out of memory.\n"); + return AVERROR(ENOMEM); + } + + pkt->stream_index = st->index; + memcpy(pkt->data, buf, adu_size); + + buf += adu_size; + len -= adu_size; + if (len) { + data->split_buf_size = len; + data->split_buf = av_malloc(data->split_buf_size); + data->split_pos = 0; + if (!data->split_buf) { + av_log(ctx, AV_LOG_ERROR, "Out of memory.\n"); + av_free_packet(pkt); + return AVERROR(ENOMEM); + } + memcpy(data->split_buf, buf, data->split_buf_size); + return 1; + } + return 0; + } else if (!continuation) { /* && adu_size > len */ + /* First fragment */ + free_fragment(data); + + data->adu_size = adu_size; + data->cur_size = len; + data->timestamp = *timestamp; + + err = avio_open_dyn_buf(&data->fragment); + if (err < 0) + return err; + + avio_write(data->fragment, buf, len); + return AVERROR(EAGAIN); + } + /* else continuation == 1 */ + + /* Fragment other than first */ + if (!data->fragment) { + av_log(ctx, AV_LOG_WARNING, + "Received packet without a start fragment; dropping.\n"); + return AVERROR(EAGAIN); + } + if (adu_size = data->adu_size || + data->timestamp != *timestamp) { + free_fragment(data); + av_log(ctx, AV_LOG_ERROR, "Invalid packet received\n"); + return AVERROR_INVALIDDATA; + } + + avio_write(data->fragment, buf, len); + data->cur_size += len; + + if (data->cur_size < data->adu_size) + return AVERROR(EAGAIN); + + err = ff_rtp_finalize_packet(pkt, &data->fragment, st->index); + if (err < 0) { + av_log(ctx, AV_LOG_ERROR, + "Error occurred when getting fragment buffer.\n"); + return err; + } + + return 0; +} + +RTPDynamicProtocolHandler ff_mpeg_audio_robust_dynamic_handler = { + .codec_type = AVMEDIA_TYPE_AUDIO, + .codec_id = AV_CODEC_ID_MP3ADU, + .init = mpa_robust_init, + .alloc = mpa_robust_new_context, + .free = mpa_robust_free_context, + .parse_packet = mpa_robust_parse_packet, + .enc_name = "mpa-robust", +}; -- cgit v1.2.3