fftools/ffmpeg: move OutputStream.sq_frame to Encoder

It is audio/video encoding-only and does not need to be visible outside
of ffmpeg_enc.c

fftools/ffmpeg.h

@@ -588,7 +588,6 @@ typedef struct OutputStream {
     Encoder *enc;
     AVCodecContext *enc_ctx;
     AVFrame *filtered_frame;
-    AVFrame *sq_frame;
     AVPacket *pkt;
     int64_t last_dropped;
     int64_t last_nb0_frames[3];

fftools/ffmpeg_enc.c

@@ -50,6 +50,8 @@ struct Encoder {
     AVFrame *last_frame;
     /* number of frames emitted by the video-encoding sync code */
     int64_t vsync_frame_number;
+
+    AVFrame *sq_frame;
 };
 
 static uint64_t dup_warning = 1000;
@@ -62,6 +64,7 @@ void enc_free(Encoder **penc)
         return;
 
     av_frame_free(&enc->last_frame);
+    av_frame_free(&enc->sq_frame);
 
     av_freep(penc);
 }
@@ -139,6 +142,7 @@ static void init_encoder_time_base(OutputStream *ost, AVRational default_time_ba
 int enc_open(OutputStream *ost, AVFrame *frame)
 {
     InputStream *ist = ost->ist;
+    Encoder              *e = ost->enc;
     AVCodecContext *enc_ctx = ost->enc_ctx;
     AVCodecContext *dec_ctx = NULL;
     const AVCodec      *enc = enc_ctx->codec;
@@ -328,6 +332,12 @@ int enc_open(OutputStream *ost, AVFrame *frame)
         return ret;
     }
 
+    if (ost->sq_idx_encode >= 0) {
+        e->sq_frame = av_frame_alloc();
+        if (!e->sq_frame)
+            return AVERROR(ENOMEM);
+    }
+
     if (ost->enc_ctx->frame_size) {
         av_assert0(ost->sq_idx_encode >= 0);
         sq_frame_samples(output_files[ost->file_index]->sq_encode,
@@ -718,16 +728,17 @@ static int encode_frame(OutputFile *of, OutputStream *ost, AVFrame *frame)
 static int submit_encode_frame(OutputFile *of, OutputStream *ost,
                                AVFrame *frame)
 {
+    Encoder *e = ost->enc;
     int ret;
 
     if (ost->sq_idx_encode < 0)
         return encode_frame(of, ost, frame);
 
     if (frame) {
-        ret = av_frame_ref(ost->sq_frame, frame);
+        ret = av_frame_ref(e->sq_frame, frame);
         if (ret < 0)
             return ret;
-        frame = ost->sq_frame;
+        frame = e->sq_frame;
     }
 
     ret = sq_send(of->sq_encode, ost->sq_idx_encode,
@@ -740,7 +751,7 @@ static int submit_encode_frame(OutputFile *of, OutputStream *ost,
     }
 
     while (1) {
-        AVFrame *enc_frame = ost->sq_frame;
+        AVFrame *enc_frame = e->sq_frame;
 
         ret = sq_receive(of->sq_encode, ost->sq_idx_encode,
                                SQFRAME(enc_frame));

fftools/ffmpeg_mux.c

@@ -663,7 +663,6 @@ static void ost_free(OutputStream **post)
     av_bsf_free(&ms->bsf_ctx);
 
     av_frame_free(&ost->filtered_frame);
-    av_frame_free(&ost->sq_frame);
     av_packet_free(&ost->pkt);
     av_dict_free(&ost->encoder_opts);
 

fftools/ffmpeg_mux_init.c

@@ -1505,10 +1505,6 @@ static int setup_sync_queues(Muxer *mux, AVFormatContext *oc, int64_t buf_size_u
             if (ost->sq_idx_encode < 0)
                 return ost->sq_idx_encode;
 
-            ost->sq_frame = av_frame_alloc();
-            if (!ost->sq_frame)
-                return AVERROR(ENOMEM);
-
             if (ms->max_frames != INT64_MAX)
                 sq_limit_frames(of->sq_encode, ost->sq_idx_encode, ms->max_frames);
         }