[FFmpeg-devel] [PATCH 5/7] avformat/rtpdec_mpeg12: add robust MPEG audio depacketization (RFC 3119)
Gilles Chanteperdrix
gilles.chanteperdrix at xenomai.org
Sun Feb 8 22:22:43 CET 2015
---
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 */
+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 < 1) {
+ 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);
+ 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",
+};
--
1.8.4
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