[FFmpeg-devel] [PATCH 5/7] avformat/rtpdec_mpeg12: add robust MPEG audio depacketization (RFC 3119)
Thomas Volkert
silvo at gmx.net
Thu Feb 12 22:41:28 CET 2015
On 02/08/2015 10:22 PM, Gilles Chanteperdrix wrote:
> ---
> libavformat/rtpdec.c | 1 +
> libavformat/rtpdec_formats.h | 1 +
> libavformat/rtpdec_mpeg12.c | 201 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 203 insertions(+)
>
> diff --git a/libavformat/rtpdec.c b/libavformat/rtpdec.c
> index 4091bdc..711a94d 100644
> --- a/libavformat/rtpdec.c
> +++ b/libavformat/rtpdec.c
> @@ -90,6 +90,7 @@ void ff_register_rtp_dynamic_payload_handlers(void)
> ff_register_dynamic_payload_handler(&ff_mp4a_latm_dynamic_handler);
> ff_register_dynamic_payload_handler(&ff_mp4v_es_dynamic_handler);
> ff_register_dynamic_payload_handler(&ff_mpeg_audio_dynamic_handler);
> + ff_register_dynamic_payload_handler(&ff_mpeg_audio_robust_dynamic_handler);
> ff_register_dynamic_payload_handler(&ff_mpeg_video_dynamic_handler);
> ff_register_dynamic_payload_handler(&ff_mpeg4_generic_dynamic_handler);
> ff_register_dynamic_payload_handler(&ff_mpegts_dynamic_handler);
> diff --git a/libavformat/rtpdec_formats.h b/libavformat/rtpdec_formats.h
> index e5aff59..3cbd0aa 100644
> --- a/libavformat/rtpdec_formats.h
> +++ b/libavformat/rtpdec_formats.h
> @@ -57,6 +57,7 @@ extern RTPDynamicProtocolHandler ff_jpeg_dynamic_handler;
> extern RTPDynamicProtocolHandler ff_mp4a_latm_dynamic_handler;
> extern RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler;
> extern RTPDynamicProtocolHandler ff_mpeg_audio_dynamic_handler;
> +extern RTPDynamicProtocolHandler ff_mpeg_audio_robust_dynamic_handler;
> extern RTPDynamicProtocolHandler ff_mpeg_video_dynamic_handler;
> extern RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler;
> extern RTPDynamicProtocolHandler ff_mpegts_dynamic_handler;
> diff --git a/libavformat/rtpdec_mpeg12.c b/libavformat/rtpdec_mpeg12.c
> index d73ff1e..7d01ef8 100644
> --- a/libavformat/rtpdec_mpeg12.c
> +++ b/libavformat/rtpdec_mpeg12.c
> @@ -71,3 +71,204 @@ RTPDynamicProtocolHandler ff_mpeg_video_dynamic_handler = {
> .parse_packet = mpeg_parse_packet,
> .static_payload_id = 32,
> };
> +
> +/* MPA-ROBUST, RFC 3119 */
Rfc 3119 was obsoleted by rfc 5219 - use this instead.
> +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;
> +
Okay.
> + if (len < 1) {
I would rather use a defined constant (#define RTP_... 1") and would
demand for one byte payload as minimum.
> + av_log(ctx, AV_LOG_ERROR, "Invalid %d bytes packet\n", len);
> + return AVERROR_INVALIDDATA;
> + }
> +
> + *cont = !!(buf[0] & 0x80);
> + if ((buf[0] & 0x40) == 0) {
> + header_size = 1;
> + *adu_size = buf[0] & ~0xc0;
> + } else {
> + if (len == 1) {
> + av_log(ctx, AV_LOG_ERROR, "Invalid %d bytes packet\n", len);
> + return AVERROR_INVALIDDATA;
> + }
> + 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;
> +
> + if (!buf) {
> + buf = &data->split_buf[data->split_pos];
> + len = data->split_buf_size - data->split_pos;
> +
> + err = mpa_robust_parse_rtp_header(ctx, buf, len, &adu_size, &continuation);
This "err" is misleading here because it stores the header size (1-byte
or 2-byte) of the ADU payload.
> + if (err < 0) {
> + av_freep(&data->split_buf);
> + return err;
> + }
> + buf += err;
> + len -= err;
> +
> + if (continuation != 0 || 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;
> + }
> +
> +
> + err = mpa_robust_parse_rtp_header(ctx, buf, len, &adu_size, &continuation);
> + if (err < 0)
> + return err;
> +
> + buf += err;
> + len -= err;
> +
> + if (continuation == 0 && 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 == 0) { /* && 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",
> +};
Okay, no ADU specific SDP parser needed here.
Please add:
- "Changelog" entry
- bump minor/micro version of libavformat
Best regards,
Thomas.
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