[FFmpeg-devel] [PATCH] movenc: Fix conversion of the first frame for extradata-less H264/HEVC

[Martin Storsjö]

Move the copying of the frame to vos_data further up in the function,
so that when writing the actual frame data for the first frame, it's
clear that the stream really is in annex b format, for the cases where
we create extradata from the first frame.

Alternatively - we could invert the checks for bitstream format. If
extradata is missing, we can't pretend that the bitstream is in
mp4 form, because we can't even know the NAL unit length prefix size
in that case.
---
 libavformat/movenc.c | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 4560064add..b61ae7aad9 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -5504,6 +5504,24 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
         memset(trk->vos_data + trk->vos_len, 0, AV_INPUT_BUFFER_PADDING_SIZE);
     }
 
+    if ((par->codec_id == AV_CODEC_ID_DNXHD ||
+         par->codec_id == AV_CODEC_ID_H264 ||
+         par->codec_id == AV_CODEC_ID_HEVC ||
+         par->codec_id == AV_CODEC_ID_TRUEHD ||
+         par->codec_id == AV_CODEC_ID_AC3 ||
+         par->codec_id == AV_CODEC_ID_H264 ||
+         par->codec_id == AV_CODEC_ID_HEVC) && !trk->vos_len) {
+        /* copy frame to create needed atoms */
+        trk->vos_len  = size;
+        trk->vos_data = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
+        if (!trk->vos_data) {
+            ret = AVERROR(ENOMEM);
+            goto err;
+        }
+        memcpy(trk->vos_data, pkt->data, size);
+        memset(trk->vos_data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
+    }
+
     if (par->codec_id == AV_CODEC_ID_AAC && pkt->size > 2 &&
         (AV_RB16(pkt->data) & 0xfff0) == 0xfff0) {
         if (!s->streams[pkt->stream_index]->nb_frames) {
@@ -5582,24 +5600,6 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
         }
     }
 
-    if ((par->codec_id == AV_CODEC_ID_DNXHD ||
-         par->codec_id == AV_CODEC_ID_H264 ||
-         par->codec_id == AV_CODEC_ID_HEVC ||
-         par->codec_id == AV_CODEC_ID_TRUEHD ||
-         par->codec_id == AV_CODEC_ID_AC3 ||
-         par->codec_id == AV_CODEC_ID_H264 ||
-         par->codec_id == AV_CODEC_ID_HEVC) && !trk->vos_len) {
-        /* copy frame to create needed atoms */
-        trk->vos_len  = size;
-        trk->vos_data = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
-        if (!trk->vos_data) {
-            ret = AVERROR(ENOMEM);
-            goto err;
-        }
-        memcpy(trk->vos_data, pkt->data, size);
-        memset(trk->vos_data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
-    }
-
     if (trk->entry >= trk->cluster_capacity) {
         unsigned new_capacity = trk->entry + MOV_INDEX_CLUSTER_SIZE;
         if (av_reallocp_array(&trk->cluster, new_capacity,
-- 
2.17.1