[FFmpeg-devel] [PATCH 2/4] avcodec/decode: simplify applying or exporting skip samples

[James Almer]

Copy packet side data to the output frame in ff_decode_frame_props_from_pkt()
instead of in discard_samples(), having the latter only applying the skip if
required.
This will be useful for the following commit.

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavcodec/decode.c | 37 ++++++++++---------------------------
 1 file changed, 10 insertions(+), 27 deletions(-)

diff --git a/libavcodec/decode.c b/libavcodec/decode.c
index 4478c8c4fe..57d38cbc54 100644
--- a/libavcodec/decode.c
+++ b/libavcodec/decode.c
@@ -293,26 +293,18 @@ static int discard_samples(AVCodecContext *avctx, AVFrame *frame, int64_t *disca
 {
     AVCodecInternal *avci = avctx->internal;
     int ret = 0;
-    uint8_t *side;
-    size_t side_size;
+    AVFrameSideData *side;
     uint32_t discard_padding = 0;
-    uint8_t skip_reason = 0;
-    uint8_t discard_reason = 0;
 
-    side = av_packet_get_side_data(avci->last_pkt_props, AV_PKT_DATA_SKIP_SAMPLES, &side_size);
-    if (side && side_size >= 10) {
-        avci->skip_samples = AV_RL32(side);
+    side = av_frame_get_side_data(frame, AV_FRAME_DATA_SKIP_SAMPLES);
+    if (side && side->size >= 10) {
+        avci->skip_samples = AV_RL32(side->data);
         avci->skip_samples = FFMAX(0, avci->skip_samples);
-        discard_padding = AV_RL32(side + 4);
+        discard_padding = AV_RL32(side->data + 4);
         av_log(avctx, AV_LOG_DEBUG, "skip %d / discard %d samples due to side data\n",
                avci->skip_samples, (int)discard_padding);
-        skip_reason = AV_RL8(side + 8);
-        discard_reason = AV_RL8(side + 9);
     }
 
-    if (!frame->buf[0])
-        return AVERROR(EAGAIN);
-
     if (frame->format == AV_SAMPLE_FMT_NONE)
         frame->format = avctx->sample_fmt;
     if (!frame->ch_layout.nb_channels) {
@@ -392,16 +384,8 @@ FF_ENABLE_DEPRECATION_WARNINGS
         }
     }
 
-    if ((avctx->flags2 & AV_CODEC_FLAG2_SKIP_MANUAL)) {
-        AVFrameSideData *fside = av_frame_new_side_data(frame, AV_FRAME_DATA_SKIP_SAMPLES, 10);
-        if (fside) {
-            AV_WL32(fside->data, avci->skip_samples);
-            AV_WL32(fside->data + 4, discard_padding);
-            AV_WL8(fside->data + 8, skip_reason);
-            AV_WL8(fside->data + 9, discard_reason);
-            avci->skip_samples = 0;
-        }
-    }
+    if (!(avctx->flags2 & AV_CODEC_FLAG2_SKIP_MANUAL))
+        av_frame_remove_side_data(frame, AV_FRAME_DATA_SKIP_SAMPLES);
 
     return ret;
 }
@@ -465,15 +449,13 @@ FF_ENABLE_DEPRECATION_WARNINGS
     }
     emms_c();
 
-    if (!got_frame)
-        av_frame_unref(frame);
-
     if (avctx->codec->type == AVMEDIA_TYPE_VIDEO) {
         ret = (!got_frame || frame->flags & AV_FRAME_FLAG_DISCARD)
                           ? AVERROR(EAGAIN)
                           : 0;
     } else if (avctx->codec->type == AVMEDIA_TYPE_AUDIO) {
-        ret = discard_samples(avctx, frame, discarded_samples);
+        ret =  !got_frame ? AVERROR(EAGAIN)
+                          : discard_samples(avctx, frame, discarded_samples);
     }
 
     if (ret == AVERROR(EAGAIN))
@@ -1386,6 +1368,7 @@ int ff_decode_frame_props_from_pkt(const AVCodecContext *avctx,
         { AV_PKT_DATA_ICC_PROFILE,                AV_FRAME_DATA_ICC_PROFILE },
         { AV_PKT_DATA_S12M_TIMECODE,              AV_FRAME_DATA_S12M_TIMECODE },
         { AV_PKT_DATA_DYNAMIC_HDR10_PLUS,         AV_FRAME_DATA_DYNAMIC_HDR_PLUS },
+        { AV_PKT_DATA_SKIP_SAMPLES,               AV_FRAME_DATA_SKIP_SAMPLES },
     };
 
     frame->pts          = pkt->pts;
-- 
2.41.0