fftools/ffmpeg: store output format separately from the muxer context

Allows accessing it without going through the muxer context. This will
be useful in the following commits, where the muxer context will be
hidden.

fftools/ffmpeg.c

@@ -2789,9 +2789,9 @@ static int init_output_stream_streamcopy(OutputStream *ost)
 
     if (!codec_tag) {
         unsigned int codec_tag_tmp;
-        if (!of->ctx->oformat->codec_tag ||
-            av_codec_get_id (of->ctx->oformat->codec_tag, par_src->codec_tag) == par_src->codec_id ||
-            !av_codec_get_tag2(of->ctx->oformat->codec_tag, par_src->codec_id, &codec_tag_tmp))
+        if (!of->format->codec_tag ||
+            av_codec_get_id (of->format->codec_tag, par_src->codec_tag) == par_src->codec_id ||
+            !av_codec_get_tag2(of->format->codec_tag, par_src->codec_id, &codec_tag_tmp))
             codec_tag = par_src->codec_tag;
     }
 
@@ -2809,7 +2809,7 @@ static int init_output_stream_streamcopy(OutputStream *ost)
     else
         ost->st->avg_frame_rate = ist->st->avg_frame_rate;
 
-    ret = avformat_transfer_internal_stream_timing_info(of->ctx->oformat, ost->st, ist->st, copy_tb);
+    ret = avformat_transfer_internal_stream_timing_info(of->format, ost->st, ist->st, copy_tb);
     if (ret < 0)
         return ret;
 
@@ -3011,7 +3011,8 @@ static int init_output_stream_encode(OutputStream *ost, AVFrame *frame)
     InputStream *ist = get_input_stream(ost);
     AVCodecContext *enc_ctx = ost->enc_ctx;
     AVCodecContext *dec_ctx = NULL;
-    AVFormatContext *oc = output_files[ost->file_index]->ctx;
+    OutputFile      *of = output_files[ost->file_index];
+    AVFormatContext *oc = of->ctx;
     int ret;
 
     set_encoder_id(output_files[ost->file_index], ost);
@@ -3072,7 +3073,8 @@ static int init_output_stream_encode(OutputStream *ost, AVFrame *frame)
         if (!(enc_ctx->time_base.num && enc_ctx->time_base.den))
             enc_ctx->time_base = av_buffersink_get_time_base(ost->filter->filter);
         if (   av_q2d(enc_ctx->time_base) < 0.001 && video_sync_method != VSYNC_PASSTHROUGH
-           && (video_sync_method == VSYNC_CFR || video_sync_method == VSYNC_VSCFR || (video_sync_method == VSYNC_AUTO && !(oc->oformat->flags & AVFMT_VARIABLE_FPS)))){
+           && (video_sync_method == VSYNC_CFR || video_sync_method == VSYNC_VSCFR ||
+               (video_sync_method == VSYNC_AUTO && !(of->format->flags & AVFMT_VARIABLE_FPS)))){
             av_log(oc, AV_LOG_WARNING, "Frame rate very high for a muxer not efficiently supporting it.\n"
                                        "Please consider specifying a lower framerate, a different muxer or -vsync 2\n");
         }
@@ -3405,7 +3407,7 @@ static int transcode_init(void)
     /* write headers for files with no streams */
     for (i = 0; i < nb_output_files; i++) {
         oc = output_files[i]->ctx;
-        if (oc->oformat->flags & AVFMT_NOSTREAMS && oc->nb_streams == 0) {
+        if (output_files[i]->format->flags & AVFMT_NOSTREAMS && oc->nb_streams == 0) {
             ret = of_check_init(output_files[i]);
             if (ret < 0)
                 goto dump_format;
@@ -4615,7 +4617,7 @@ int main(int argc, char **argv)
     }
 
     for (i = 0; i < nb_output_files; i++) {
-        if (strcmp(output_files[i]->ctx->oformat->name, "rtp"))
+        if (strcmp(output_files[i]->format->name, "rtp"))
             want_sdp = 0;
     }
 

fftools/ffmpeg.h

@@ -579,6 +579,8 @@ typedef struct OutputStream {
 typedef struct OutputFile {
     int index;
 
+    const AVOutputFormat *format;
+
     AVFormatContext *ctx;
     AVDictionary *opts;
     int ost_index;       /* index of the first stream in output_streams */

fftools/ffmpeg_opt.c

@@ -2332,6 +2332,7 @@ static int open_output_file(OptionsContext *o, const char *filename)
     }
 
     of->ctx = oc;
+    of->format = oc->oformat;
     if (o->recording_time != INT64_MAX)
         oc->duration = o->recording_time;