avformat: refactor ff_stream_encode_params_copy() to stream_params_copy()

Addresses http://ffmpeg.org/pipermail/ffmpeg-devel/2022-August/299726.html

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavformat/avformat.c

@@ -235,6 +235,72 @@ int ff_stream_side_data_copy(AVStream *dst, const AVStream *src)
     return 0;
 }
 
+/**
+ * Copy all stream parameters from source to destination stream, with the
+ * exception of the index field, which is usually set by avformat_new_stream().
+ *
+ * @param dst pointer to destination AVStream
+ * @param src pointer to source AVStream
+ * @return >=0 on success, AVERROR code on error
+ */
+static int stream_params_copy(AVStream *dst, const AVStream *src)
+{
+    int ret;
+
+    dst->id                  = src->id;
+    dst->time_base           = src->time_base;
+    dst->start_time          = src->start_time;
+    dst->duration            = src->duration;
+    dst->nb_frames           = src->nb_frames;
+    dst->disposition         = src->disposition;
+    dst->discard             = src->discard;
+    dst->sample_aspect_ratio = src->sample_aspect_ratio;
+    dst->avg_frame_rate      = src->avg_frame_rate;
+    dst->event_flags         = src->event_flags;
+    dst->r_frame_rate        = src->r_frame_rate;
+    dst->pts_wrap_bits       = src->pts_wrap_bits;
+
+    av_dict_free(&dst->metadata);
+    ret = av_dict_copy(&dst->metadata, src->metadata, 0);
+    if (ret < 0)
+        return ret;
+
+    ret = avcodec_parameters_copy(dst->codecpar, src->codecpar);
+    if (ret < 0)
+        return ret;
+
+    ret = ff_stream_side_data_copy(dst, src);
+    if (ret < 0)
+        return ret;
+
+    av_packet_unref(&dst->attached_pic);
+    if (src->attached_pic.data) {
+        ret = av_packet_ref(&dst->attached_pic, &src->attached_pic);
+        if (ret < 0)
+            return ret;
+    }
+
+    return 0;
+}
+
+AVStream *ff_stream_clone(AVFormatContext *dst_ctx, const AVStream *src)
+{
+    AVStream *st;
+    int ret;
+
+    st = avformat_new_stream(dst_ctx, NULL);
+    if (!st)
+        return NULL;
+
+    ret = stream_params_copy(st, src);
+    if (ret < 0) {
+        ff_remove_stream(dst_ctx, st);
+        return NULL;
+    }
+
+    return st;
+}
+
 AVProgram *av_new_program(AVFormatContext *ac, int id)
 {
     AVProgram *program = NULL;

libavformat/fifo.c

@@ -505,13 +505,9 @@ static int fifo_mux_init(AVFormatContext *avf, const AVOutputFormat *oformat,
     avf2->flags = avf->flags;
 
     for (i = 0; i < avf->nb_streams; ++i) {
-        AVStream *st = avformat_new_stream(avf2, NULL);
+        AVStream *st = ff_stream_clone(avf2, avf->streams[i]);
         if (!st)
             return AVERROR(ENOMEM);
-
-        ret = ff_stream_encode_params_copy(st, avf->streams[i]);
-        if (ret < 0)
-            return ret;
     }
 
     return 0;

libavformat/internal.h

@@ -625,6 +625,17 @@ enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags);
  */
 int ff_stream_side_data_copy(AVStream *dst, const AVStream *src);
 
+/**
+ * Create a new stream and copy to it all parameters from a source stream, with
+ * the exception of the index field, which is set when the new stream is
+ * created.
+ *
+ * @param dst_ctx pointer to the context in which the new stream is created
+ * @param src pointer to source AVStream
+ * @return pointer to the new stream or NULL on error
+ */
+AVStream *ff_stream_clone(AVFormatContext *dst_ctx, const AVStream *src);
+
 /**
  * Wrap ffurl_move() and log if error happens.
  *

libavformat/mux.h

@@ -113,15 +113,6 @@ int ff_format_shift_data(AVFormatContext *s, int64_t read_start, int shift_size)
  */
 int ff_format_output_open(AVFormatContext *s, const char *url, AVDictionary **options);
 
-/**
- * Copy encoding parameters from source to destination stream
- *
- * @param dst pointer to destination AVStream
- * @param src pointer to source AVStream
- * @return >=0 on success, AVERROR code on error
- */
-int ff_stream_encode_params_copy(AVStream *dst, const AVStream *src);
-
 /**
  * Parse creation_time in AVFormatContext metadata if exists and warn if the
  * parsing fails.

libavformat/mux_utils.c

@@ -121,34 +121,6 @@ int ff_format_output_open(AVFormatContext *s, const char *url, AVDictionary **op
     return 0;
 }
 
-int ff_stream_encode_params_copy(AVStream *dst, const AVStream *src)
-{
-    int ret;
-
-    dst->id                  = src->id;
-    dst->time_base           = src->time_base;
-    dst->nb_frames           = src->nb_frames;
-    dst->disposition         = src->disposition;
-    dst->sample_aspect_ratio = src->sample_aspect_ratio;
-    dst->avg_frame_rate      = src->avg_frame_rate;
-    dst->r_frame_rate        = src->r_frame_rate;
-
-    av_dict_free(&dst->metadata);
-    ret = av_dict_copy(&dst->metadata, src->metadata, 0);
-    if (ret < 0)
-        return ret;
-
-    ret = avcodec_parameters_copy(dst->codecpar, src->codecpar);
-    if (ret < 0)
-        return ret;
-
-    ret = ff_stream_side_data_copy(dst, src);
-    if (ret < 0)
-        return ret;
-
-    return 0;
-}
-
 int ff_parse_creation_time_metadata(AVFormatContext *s, int64_t *timestamp, int return_seconds)
 {
     AVDictionaryEntry *entry;

libavformat/segment.c

@@ -167,11 +167,9 @@ static int segment_mux_init(AVFormatContext *s)
         AVStream *st, *ist = s->streams[i];
         AVCodecParameters *ipar = ist->codecpar, *opar;
 
-        if (!(st = avformat_new_stream(oc, NULL)))
+        st = ff_stream_clone(oc, ist);
+        if (!st)
             return AVERROR(ENOMEM);
-        ret = ff_stream_encode_params_copy(st, ist);
-        if (ret < 0)
-            return ret;
         opar = st->codecpar;
         if (!oc->oformat->codec_tag ||
             av_codec_get_id (oc->oformat->codec_tag, ipar->codec_tag) == opar->codec_id ||

libavformat/tee.c

@@ -284,14 +284,11 @@ static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)
         }
         tee_slave->stream_map[i] = stream_count++;
 
-        if (!(st2 = avformat_new_stream(avf2, NULL))) {
+        st2 = ff_stream_clone(avf2, st);
+        if (!st2) {
             ret = AVERROR(ENOMEM);
             goto end;
         }
-
-        ret = ff_stream_encode_params_copy(st2, st);
-        if (ret < 0)
-            goto end;
     }
 
     ret = ff_format_output_open(avf2, filename, &options);

libavformat/webm_chunk.c

@@ -91,12 +91,10 @@ static int webm_chunk_init(AVFormatContext *s)
     if ((ret = av_dict_copy(&oc->metadata, s->metadata, 0)) < 0)
         return ret;
 
-    if (!(st = avformat_new_stream(oc, NULL)))
+    st = ff_stream_clone(oc, ost);
+    if (!st)
         return AVERROR(ENOMEM);
 
-    if ((ret = ff_stream_encode_params_copy(st, ost)) < 0)
-        return ret;
-
     if (wc->http_method)
         if ((ret = av_dict_set(&dict, "method", wc->http_method, 0)) < 0)
             return ret;