@@ -1503,6 +1503,7 @@ static int av_encode(AVFormatContext **output_files,

     /* for each output stream, we compute the right encoding parameters */

     for(i=0;i<nb_ostreams;i++) {

         ost = ost_table[i];

+        os = output_files[ost->file_index];

         ist = ist_table[ost->source_index];

         codec = ost->st->codec;

@@ -1516,7 +1517,14 @@ static int av_encode(AVFormatContext **output_files,

             /* if stream_copy is selected, no need to decode or encode */

             codec->codec_id = icodec->codec_id;

             codec->codec_type = icodec->codec_type;

-            if(!codec->codec_tag) codec->codec_tag = icodec->codec_tag;

+

+            if(!codec->codec_tag){

+                if(   !os->oformat->codec_tag

+                   || av_codec_get_id (os->oformat->codec_tag, icodec->codec_tag) > 0

+                   || av_codec_get_tag(os->oformat->codec_tag, icodec->codec_id) <= 0)

+                    codec->codec_tag = icodec->codec_tag;

+            }

+

             codec->bit_rate = icodec->bit_rate;

             codec->extradata= icodec->extradata;

             codec->extradata_size= icodec->extradata_size;