Fix libx264.c to not drop SEI userdata from x264 encoder.

Most muxers in ffmpeg ignore the SEI if it is placed in extradata, so instead
it has to be catted to the front of the first video frame.

Originally committed as revision 19310 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/libx264.c

@@ -30,6 +30,8 @@ typedef struct X264Context {
     x264_param_t params;
     x264_t *enc;
     x264_picture_t pic;
+    uint8_t *sei;
+    int sei_size;
     AVFrame out_pic;
 } X264Context;
 
@@ -51,13 +53,30 @@ X264_log(void *p, int level, const char *fmt, va_list args)
 
 
 static int
-encode_nals(uint8_t *buf, int size, x264_nal_t *nals, int nnal)
+encode_nals(AVCodecContext *ctx, uint8_t *buf, int size, x264_nal_t *nals, int nnal, int skip_sei)
 {
+    X264Context *x4 = ctx->priv_data;
     uint8_t *p = buf;
-    int i;
+    int i, s;
+
+    /* Write the SEI as part of the first frame. */
+    if(x4->sei_size > 0 && nnal > 0)
+    {
+        memcpy(p, x4->sei, x4->sei_size);
+        p += x4->sei_size;
+        x4->sei_size = 0;
+    }
 
     for(i = 0; i < nnal; i++){
-        int s = x264_nal_encode(p, &size, 1, nals + i);
+        /* Don't put the SEI in extradata. */
+        if(skip_sei && nals[i].i_type == NAL_SEI)
+        {
+            x4->sei = av_malloc( 5 + nals[i].i_payload * 4 / 3 );
+            if(x264_nal_encode(x4->sei, &x4->sei_size, 1, nals + i) < 0)
+                return -1;
+            continue;
+        }
+        s = x264_nal_encode(p, &size, 1, nals + i);
         if(s < 0)
             return -1;
         p += s;
@@ -92,7 +111,7 @@ X264_frame(AVCodecContext *ctx, uint8_t *buf, int bufsize, void *data)
                            &pic_out))
         return -1;
 
-    bufsize = encode_nals(buf, bufsize, nal, nnal);
+    bufsize = encode_nals(ctx, buf, bufsize, nal, nnal, 0);
     if(bufsize < 0)
         return -1;
 
@@ -125,6 +144,7 @@ X264_close(AVCodecContext *avctx)
     X264Context *x4 = avctx->priv_data;
 
     av_freep(&avctx->extradata);
+    av_free(x4->sei);
 
     if(x4->enc)
         x264_encoder_close(x4->enc);
@@ -137,6 +157,7 @@ X264_init(AVCodecContext *avctx)
 {
     X264Context *x4 = avctx->priv_data;
 
+    x4->sei_size = 0;
     x264_param_default(&x4->params);
 
     x4->params.pf_log = X264_log;
@@ -284,7 +305,7 @@ X264_init(AVCodecContext *avctx)
             s += 5 + nal[i].i_payload * 4 / 3;
 
         avctx->extradata = av_malloc(s);
-        avctx->extradata_size = encode_nals(avctx->extradata, s, nal, nnal);
+        avctx->extradata_size = encode_nals(avctx, avctx->extradata, s, nal, nnal, 1);
     }
 
     return 0;