From 22470510d1f9441e848bbe107c7963b6d492b47f Mon Sep 17 00:00:00 2001 From: Gilles Chanteperdrix Date: Fri, 13 Feb 2015 22:51:33 +0100 Subject: avformat/rtpdec_mpeg12: add robust MPEG audio depacketization (RFC 5219) Reviewed-by: Thomas Volkert Signed-off-by: Michael Niedermayer --- libavformat/rtpdec_mpeg12.c | 204 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 204 insertions(+) (limited to 'libavformat/rtpdec_mpeg12.c') diff --git a/libavformat/rtpdec_mpeg12.c b/libavformat/rtpdec_mpeg12.c index d73ff1e144..d99c507716 100644 --- a/libavformat/rtpdec_mpeg12.c +++ b/libavformat/rtpdec_mpeg12.c @@ -2,6 +2,9 @@ * Common code for the RTP depacketization of MPEG-1/2 formats. * Copyright (c) 2002 Fabrice Bellard * + * RTP parser for loss tolerant payload format for MP3 audio (RFC 5219) + * Copyright (c) 2015 Gilles Chanteperdrix + * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or @@ -23,6 +26,8 @@ #include "libavutil/intreadwrite.h" #include "rtpdec_formats.h" +#define RTP_MPA_PAYLOAD_HEADER_SIZE 1 + static av_cold int mpeg_init(AVFormatContext *ctx, int st_index, PayloadContext *data) { if (st_index < 0) @@ -71,3 +76,202 @@ RTPDynamicProtocolHandler ff_mpeg_video_dynamic_handler = { .parse_packet = mpeg_parse_packet, .static_payload_id = 32, }; + +/* MPA-ROBUST, RFC 5219 */ +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_if_needed(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_if_needed(data); + 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 < RTP_MPA_PAYLOAD_HEADER_SIZE + 1) { + 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 = (buf - data->split_buf) + 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_if_needed(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_if_needed(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."); + 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