fftools/ffmpeg_mux: embed OutputStream in a MuxStream

This is now possible since OutputStream is a child of OutputFile and the
code allocating it can access MuxStream. Avoids the overhead and extra
complexity of allocating two objects instead of one.

Similar to what was previously done for OutputFile/Muxer.

fftools/ffmpeg_mux.c

@@ -45,6 +45,11 @@ static Muxer *mux_from_of(OutputFile *of)
     return (Muxer*)of;
 }
 
+static MuxStream *ms_from_ost(OutputStream *ost)
+{
+    return (MuxStream*)ost;
+}
+
 static int64_t filesize(AVIOContext *pb)
 {
     int64_t ret = -1;
@@ -60,7 +65,7 @@ static int64_t filesize(AVIOContext *pb)
 
 static int write_packet(Muxer *mux, OutputStream *ost, AVPacket *pkt)
 {
-    MuxStream *ms = &mux->streams[ost->index];
+    MuxStream *ms = ms_from_ost(ost);
     AVFormatContext *s = mux->fc;
     AVStream *st = ost->st;
     int64_t fs;
@@ -251,7 +256,7 @@ finish:
 
 static int queue_packet(Muxer *mux, OutputStream *ost, AVPacket *pkt)
 {
-    MuxStream *ms = &mux->streams[ost->index];
+    MuxStream *ms = ms_from_ost(ost);
     AVPacket *tmp_pkt = NULL;
     int ret;
 
@@ -409,8 +414,8 @@ static int thread_start(Muxer *mux)
 
     /* flush the muxing queues */
     for (int i = 0; i < fc->nb_streams; i++) {
-        MuxStream     *ms = &mux->streams[i];
         OutputStream *ost = mux->of.streams[i];
+        MuxStream     *ms = ms_from_ost(ost);
         AVPacket *pkt;
 
         /* try to improve muxing time_base (only possible if nothing has been written yet) */
@@ -626,9 +631,11 @@ int of_write_trailer(OutputFile *of)
 static void ost_free(OutputStream **post)
 {
     OutputStream *ost = *post;
+    MuxStream *ms;
 
     if (!ost)
         return;
+    ms = ms_from_ost(ost);
 
     if (ost->logfile) {
         if (fclose(ost->logfile))
@@ -638,6 +645,13 @@ static void ost_free(OutputStream **post)
         ost->logfile = NULL;
     }
 
+    if (ms->muxing_queue) {
+        AVPacket *pkt;
+        while (av_fifo_read(ms->muxing_queue, &pkt, 1) >= 0)
+            av_packet_free(&pkt);
+        av_fifo_freep2(&ms->muxing_queue);
+    }
+
     av_bsf_free(&ost->bsf_ctx);
 
     av_frame_free(&ost->filtered_frame);
@@ -697,19 +711,6 @@ void of_close(OutputFile **pof)
     sq_free(&of->sq_encode);
     sq_free(&mux->sq_mux);
 
-    for (int i = 0; i < mux->nb_streams; i++) {
-        MuxStream *ms = &mux->streams[i];
-        AVPacket *pkt;
-
-        if (!ms->muxing_queue)
-            continue;
-
-        while (av_fifo_read(ms->muxing_queue, &pkt, 1) >= 0)
-            av_packet_free(&pkt);
-        av_fifo_freep2(&ms->muxing_queue);
-    }
-    av_freep(&mux->streams);
-
     for (int i = 0; i < of->nb_streams; i++)
         ost_free(&of->streams[i]);
     av_freep(&of->streams);

fftools/ffmpeg_mux.h

@@ -35,6 +35,8 @@
 #include "libavutil/thread.h"
 
 typedef struct MuxStream {
+    OutputStream ost;
+
     /* the packets are buffered here until the muxer is ready to be initialized */
     AVFifo *muxing_queue;
 
@@ -57,9 +59,6 @@ typedef struct Muxer {
     pthread_t    thread;
     ThreadQueue *tq;
 
-    MuxStream *streams;
-    int     nb_streams;
-
     AVDictionary *opts;
 
     int thread_queue_size;

fftools/ffmpeg_mux_init.c

@@ -168,6 +168,7 @@ static OutputStream *new_output_stream(Muxer *mux, OptionsContext *o,
                                        enum AVMediaType type, int source_index)
 {
     AVFormatContext *oc = mux->fc;
+    MuxStream     *ms;
     OutputStream *ost;
     const AVCodec *enc;
     AVStream *st = avformat_new_stream(oc, NULL);
@@ -183,7 +184,14 @@ static OutputStream *new_output_stream(Muxer *mux, OptionsContext *o,
     if (oc->nb_streams - 1 < o->nb_streamid_map)
         st->id = o->streamid_map[oc->nb_streams - 1];
 
-    ost = ALLOC_ARRAY_ELEM(mux->of.streams, mux->of.nb_streams);
+    ms  = allocate_array_elem(&mux->of.streams, sizeof(MuxStream),
+                              &mux->of.nb_streams);
+    ost = &ms->ost;
+
+    ms->muxing_queue = av_fifo_alloc2(8, sizeof(AVPacket*), 0);
+    if (!ms->muxing_queue)
+        report_and_exit(AVERROR(ENOMEM));
+    ms->last_mux_dts = AV_NOPTS_VALUE;
 
     ost->file_index = nb_output_files - 1;
     ost->index      = idx;
@@ -1900,19 +1908,6 @@ int of_open(OptionsContext *o, const char *filename)
 
     of->url        = filename;
 
-    mux->streams = av_calloc(oc->nb_streams, sizeof(*mux->streams));
-    if (!mux->streams)
-        return AVERROR(ENOMEM);
-    mux->nb_streams = oc->nb_streams;
-
-    for (int i = 0; i < mux->nb_streams; i++) {
-        MuxStream *ms = &mux->streams[i];
-        ms->muxing_queue = av_fifo_alloc2(8, sizeof(AVPacket*), 0);
-        if (!ms->muxing_queue)
-            return AVERROR(ENOMEM);
-        ms->last_mux_dts = AV_NOPTS_VALUE;
-    }
-
     /* write the header for files with no streams */
     if (of->format->flags & AVFMT_NOSTREAMS && oc->nb_streams == 0) {
         int ret = mux_check_init(mux);