libavformat/flvenc: support for codec configuration change mid stream

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/flvenc.c

@@ -566,6 +566,19 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
     else
         flags_size = 1;
 
+    if (par->codec_id == AV_CODEC_ID_AAC || par->codec_id == AV_CODEC_ID_H264
+            || par->codec_id == AV_CODEC_ID_MPEG4) {
+        int side_size = 0;
+        uint8_t *side = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, &side_size);
+        if (side && side_size > 0 && (side_size != par->extradata_size || memcmp(side, par->extradata, side_size))) {
+            av_free(par->extradata);
+            par->extradata = av_mallocz(side_size + AV_INPUT_BUFFER_PADDING_SIZE);
+            memcpy(par->extradata, side, side_size);
+            par->extradata_size = side_size;
+            flv_write_codec_header(s, par);
+        }
+    }
+
     if (flv->delay == AV_NOPTS_VALUE)
         flv->delay = -pkt->dts;