[FFmpeg-devel] [PATCH] avcodec/h264_parser: export sei recovery frame count as side data

[Michael Niedermayer]

TODO: split between API addition and h264 parser change

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
---
 libavcodec/avcodec.h     |   13 +++++++++++++
 libavcodec/h264_parser.c |    2 ++
 libavcodec/parser.c      |    1 +
 libavformat/utils.c      |    6 ++++++
 4 files changed, 22 insertions(+)

diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 9a24c96..ed7b914 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -1115,6 +1115,12 @@ enum AVPacketSideDataType {
      * side data includes updated metadata which appeared in the stream.
      */
     AV_PKT_DATA_METADATA_UPDATE,
+
+    /**
+     * signed LE 32bit integer specifying the number of codec specific units
+     * (frame_num(h264) or POC(HEVC)) until the decoder output is clear of artifacts
+     */
+    AV_PKT_DATA_DECODER_RECOVERY,
 };
 
 typedef struct AVPacketSideData {
@@ -4263,6 +4269,13 @@ typedef struct AVCodecParserContext {
      * For example, this corresponds to H.264 PicOrderCnt.
      */
     int output_picture_number;
+
+    /**
+     * Number of frame_num or POC units until decoding is practically clear of artifacts.
+     * The exact unit depends on the video standard, H.264 stores frame count,
+     * HEVC, POC.
+     */
+    int recovery_frame_cnt;
 } AVCodecParserContext;
 
 typedef struct AVCodecParser {
diff --git a/libavcodec/h264_parser.c b/libavcodec/h264_parser.c
index ea0ab98..6fa04c8 100644
--- a/libavcodec/h264_parser.c
+++ b/libavcodec/h264_parser.c
@@ -491,6 +491,8 @@ static int h264_parse(AVCodecParserContext *s,
 
     parse_nal_units(s, avctx, buf, buf_size);
 
+    s->recovery_frame_cnt = h->sei_recovery_frame_cnt;
+
     if (h->sei_cpb_removal_delay >= 0) {
         s->dts_sync_point    = h->sei_buffering_period_present;
         s->dts_ref_dts_delta = h->sei_cpb_removal_delay;
diff --git a/libavcodec/parser.c b/libavcodec/parser.c
index 3169e25..74525b9 100644
--- a/libavcodec/parser.c
+++ b/libavcodec/parser.c
@@ -84,6 +84,7 @@ found:
     s->dts_sync_point       = INT_MIN;
     s->dts_ref_dts_delta    = INT_MIN;
     s->pts_dts_delta        = INT_MIN;
+    s->recovery_frame_cnt   = INT_MIN;
     return s;
 
 err_out:
diff --git a/libavformat/utils.c b/libavformat/utils.c
index d84d605..45ce945 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1135,6 +1135,12 @@ static void compute_pkt_fields(AVFormatContext *s, AVStream *st,
     if (s->flags & AVFMT_FLAG_NOFILLIN)
         return;
 
+    if (pc && pc->recovery_frame_cnt >= 0) {
+        uint8_t *side_data = av_packet_new_side_data(pkt, AV_PKT_DATA_DECODER_RECOVERY, 4);
+        if (side_data)
+            AV_WL32(side_data, pc->recovery_frame_cnt);
+    }
+
     if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && pkt->dts != AV_NOPTS_VALUE) {
         if (pkt->dts == pkt->pts && st->last_dts_for_order_check != AV_NOPTS_VALUE) {
             if (st->last_dts_for_order_check <= pkt->dts) {
-- 
1.7.9.5