cmdutils: allow precisely specifying a stream for AVOptions.

avconv.c

@@ -674,8 +674,10 @@ static OutputStream *new_output_stream(AVFormatContext *oc, int file_idx, AVCode
     ost->index = idx;
     ost->st    = st;
     ost->enc   = codec;
-    if (codec)
+    if (codec) {
-        ost->opts  = filter_codec_opts(codec_opts, codec->id, 1);
+        st->codec->codec_type = codec->type;
+        ost->opts  = filter_codec_opts(codec_opts, codec->id, oc, st);
+    }
 
     avcodec_get_context_defaults3(st->codec, codec);
 
@@ -3137,7 +3139,7 @@ static int opt_input_file(const char *opt, const char *filename)
         ist->st = st;
         ist->file_index = nb_input_files;
         ist->discard = 1;
-        ist->opts = filter_codec_opts(codec_opts, ist->st->codec->codec_id, 0);
+        ist->opts = filter_codec_opts(codec_opts, ist->st->codec->codec_id, ic, st);
 
         if (i < nb_ts_scale)
             ist->ts_scale = ts_scale[i];

avplay.c

@@ -2134,7 +2134,7 @@ static int stream_component_open(VideoState *is, int stream_index)
         return -1;
     avctx = ic->streams[stream_index]->codec;
 
-    opts = filter_codec_opts(codec_opts, avctx->codec_id, 0);
+    opts = filter_codec_opts(codec_opts, avctx->codec_id, ic, ic->streams[stream_index]);
 
     /* prepare audio output */
     if (avctx->codec_type == AVMEDIA_TYPE_AUDIO) {

cmdutils.c

@@ -289,7 +289,14 @@ unknown_opt:
 int opt_default(const char *opt, const char *arg)
 {
     const AVOption *o;
-    if ((o = av_opt_find(avcodec_opts[0], opt, NULL, 0, AV_OPT_SEARCH_CHILDREN)) ||
+    char opt_stripped[128];
+    const char *p;
+
+    if (!(p = strchr(opt, ':')))
+        p = opt + strlen(opt);
+    av_strlcpy(opt_stripped, opt, FFMIN(sizeof(opt_stripped), p - opt + 1));
+
+    if ((o = av_opt_find(avcodec_opts[0], opt_stripped, NULL, 0, AV_OPT_SEARCH_CHILDREN)) ||
          ((opt[0] == 'v' || opt[0] == 'a' || opt[0] == 's') &&
           (o = av_opt_find(avcodec_opts[0], opt+1, NULL, 0, 0))))
         av_dict_set(&codec_opts, opt, arg, FLAGS);
@@ -782,12 +789,42 @@ FILE *get_preset_file(char *filename, size_t filename_size,
     return f;
 }
 
-AVDictionary *filter_codec_opts(AVDictionary *opts, enum CodecID codec_id, int encoder)
+int check_stream_specifier(AVFormatContext *s, AVStream *st, const char *spec)
+{
+    if (*spec <= '9' && *spec >= '0')                                        /* opt:index */
+        return strtol(spec, NULL, 0) == st->index;
+    else if (*spec == 'v' || *spec == 'a' || *spec == 's' || *spec == 'd') { /* opt:[vasd] */
+        enum AVMediaType type;
+
+        switch (*spec++) {
+        case 'v': type = AVMEDIA_TYPE_VIDEO;    break;
+        case 'a': type = AVMEDIA_TYPE_AUDIO;    break;
+        case 's': type = AVMEDIA_TYPE_SUBTITLE; break;
+        case 'd': type = AVMEDIA_TYPE_DATA;     break;
+        }
+        if (type != st->codec->codec_type)
+            return 0;
+        if (*spec++ == ':') {                                   /* possibly followed by :index */
+            int i, index = strtol(spec, NULL, 0);
+            for (i = 0; i < s->nb_streams; i++)
+                if (s->streams[i]->codec->codec_type == type && index-- == 0)
+                   return i == st->index;
+            return 0;
+        }
+        return 1;
+    } else if (!*spec) /* empty specifier, matches everything */
+        return 1;
+
+    av_log(s, AV_LOG_ERROR, "Invalid stream specifier: %s.\n", spec);
+    return AVERROR(EINVAL);
+}
+
+AVDictionary *filter_codec_opts(AVDictionary *opts, enum CodecID codec_id, AVFormatContext *s, AVStream *st)
 {
     AVDictionary    *ret = NULL;
     AVDictionaryEntry *t = NULL;
-    AVCodec       *codec = encoder ? avcodec_find_encoder(codec_id) : avcodec_find_decoder(codec_id);
+    AVCodec       *codec = s->oformat ? avcodec_find_encoder(codec_id) : avcodec_find_decoder(codec_id);
-    int            flags = encoder ? AV_OPT_FLAG_ENCODING_PARAM : AV_OPT_FLAG_DECODING_PARAM;
+    int            flags = s->oformat ? AV_OPT_FLAG_ENCODING_PARAM : AV_OPT_FLAG_DECODING_PARAM;
     char          prefix = 0;
 
     if (!codec)
@@ -800,11 +837,24 @@ AVDictionary *filter_codec_opts(AVDictionary *opts, enum CodecID codec_id, int e
     }
 
     while (t = av_dict_get(opts, "", t, AV_DICT_IGNORE_SUFFIX)) {
+        char *p = strchr(t->key, ':');
+
+        /* check stream specification in opt name */
+        if (p)
+            switch (check_stream_specifier(s, st, p + 1)) {
+            case  1: *p = 0; break;
+            case  0:         continue;
+            default:         return NULL;
+            }
+
         if (av_opt_find(avcodec_opts[0], t->key, NULL, flags, 0) ||
             (codec && codec->priv_class && av_opt_find(&codec->priv_class, t->key, NULL, flags, 0)))
             av_dict_set(&ret, t->key, t->value, 0);
         else if (t->key[0] == prefix && av_opt_find(avcodec_opts[0], t->key+1, NULL, flags, 0))
             av_dict_set(&ret, t->key+1, t->value, 0);
+
+        if (p)
+            *p = ':';
     }
     return ret;
 }
@@ -822,7 +872,7 @@ AVDictionary **setup_find_stream_info_opts(AVFormatContext *s, AVDictionary *cod
         return NULL;
     }
     for (i = 0; i < s->nb_streams; i++)
-        opts[i] = filter_codec_opts(codec_opts, s->streams[i]->codec->codec_id, 0);
+        opts[i] = filter_codec_opts(codec_opts, s->streams[i]->codec->codec_id, s, s->streams[i]);
     return opts;
 }
 

cmdutils.h

@@ -148,16 +148,28 @@ void show_help_options(const OptionDef *options, const char *msg, int mask, int
 void parse_options(int argc, char **argv, const OptionDef *options,
                    void (* parse_arg_function)(const char*));
 
+/**
+ * Check if the given stream matches a stream specifier.
+ *
+ * @param s  Corresponding format context.
+ * @param st Stream from s to be checked.
+ * @param spec A stream specifier of the [v|a|s|d]:[<stream index>] form.
+ *
+ * @return 1 if the stream matches, 0 if it doesn't, <0 on error
+ */
+int check_stream_specifier(AVFormatContext *s, AVStream *st, const char *spec);
+
 /**
  * Filter out options for given codec.
  *
  * Create a new options dictionary containing only the options from
  * opts which apply to the codec with ID codec_id.
  *
- * @param encoder if non-zero the codec is an encoder, otherwise is a decoder
+ * @param s Corresponding format context.
+ * @param st A stream from s for which the options should be filtered.
  * @return a pointer to the created dictionary
  */
-AVDictionary *filter_codec_opts(AVDictionary *opts, enum CodecID codec_id, int encoder);
+AVDictionary *filter_codec_opts(AVDictionary *opts, enum CodecID codec_id, AVFormatContext *s, AVStream *st);
 
 /**
  * Setup AVCodecContext options for avformat_find_stream_info().

doc/fftools-common-opts.texi

@@ -114,5 +114,22 @@ muxer:
 ffmpeg -i input.flac -id3v2_version 3 out.mp3
 @end example
 
+You can precisely specify which stream(s) should the codec AVOption apply to by
+appending a stream specifier of the form
+@option{[:@var{stream_type}][:@var{stream_index}]} to the option name.
+@var{stream_type} is 'v' for video, 'a' for audio and 's' for subtitle streams.
+@var{stream_index} is a global stream index when @var{stream_type} isn't
+given, otherwise it counts streams of the given type only. As always, the index
+is zero-based. For example
+@example
+-foo -- applies to all applicable streams
+-foo:v -- applies to all video streams
+-foo:a:2 -- applies to the third audio stream
+-foo:0 -- applies to the first stream
+@end example
+
 Note -nooption syntax cannot be used for boolean AVOptions, use -option
 0/-option 1.
+
+Note2 old undocumented way of specifying per-stream AVOptions by prepending
+v/a/s to the options name is now obsolete and will be removed soon.

ffmpeg.c

@@ -683,7 +683,7 @@ static OutputStream *new_output_stream(AVFormatContext *oc, int file_idx, AVCode
     ost->st    = st;
     ost->enc   = codec;
     if (codec)
-        ost->opts  = filter_codec_opts(codec_opts, codec->id, 1);
+        ost->opts  = filter_codec_opts(codec_opts, codec->id, oc, st);
 
     avcodec_get_context_defaults3(st->codec, codec);
 
@@ -3293,7 +3293,7 @@ static int opt_input_file(const char *opt, const char *filename)
         ist->st = st;
         ist->file_index = nb_input_files;
         ist->discard = 1;
-        ist->opts = filter_codec_opts(codec_opts, ist->st->codec->codec_id, 0);
+        ist->opts = filter_codec_opts(codec_opts, ist->st->codec->codec_id, ic, st);
 
         if (i < nb_ts_scale)
             ist->ts_scale = ts_scale[i];