ffmpeg: use avcodec_get_name to report missing en/decoders.

ffmpeg.c

@@ -2436,8 +2436,8 @@ static int transcode(AVFormatContext **output_files,
             AVCodec *codec = ost->enc;
             AVCodecContext *dec = input_streams[ost->source_index].st->codec;
             if (!codec) {
-                snprintf(error, sizeof(error), "Encoder (codec id %d) not found for output stream #%d.%d",
-                         ost->st->codec->codec_id, ost->file_index, ost->index);
+                snprintf(error, sizeof(error), "Encoder (codec %s) not found for output stream #%d.%d",
+                         avcodec_get_name(ost->st->codec->codec_id), ost->file_index, ost->index);
                 ret = AVERROR(EINVAL);
                 goto dump_format;
             }
@@ -2473,8 +2473,8 @@ static int transcode(AVFormatContext **output_files,
             if (!codec)
                 codec = avcodec_find_decoder(ist->st->codec->codec_id);
             if (!codec) {
-                snprintf(error, sizeof(error), "Decoder (codec id %d) not found for input stream #%d.%d",
-                        ist->st->codec->codec_id, ist->file_index, ist->st->index);
+                snprintf(error, sizeof(error), "Decoder (codec %s) not found for input stream #%d.%d",
+                        avcodec_get_name(ist->st->codec->codec_id), ist->file_index, ist->st->index);
                 ret = AVERROR(EINVAL);
                 goto dump_format;
             }