[FFmpeg-devel] [PATCH] ffplay: fix and extend option -codec option

[Stefano Sabatini]

Allow to specify the stream for which the codec name is set. Also make
parsing and error reporting more robust.
---
 doc/ffplay.texi |    6 ++++--
 ffplay.c        |   50 ++++++++++++++++++++++++++++++++++++++++----------
 2 files changed, 44 insertions(+), 12 deletions(-)

diff --git a/doc/ffplay.texi b/doc/ffplay.texi
index e2bded7..7923492 100644
--- a/doc/ffplay.texi
+++ b/doc/ffplay.texi
@@ -134,8 +134,10 @@ Exit when video is done playing.
 Exit if any key is pressed.
 @item -exitonmousedown
 Exit if any mouse button is pressed.
- at item -codec:@var{stream_type}
-Force a specific decoder implementation
+
+ at item -codec:@var{stream_specifier} @var{codec_name}
+Force a specific decoder implementation for the stream specified by
+ at var{stream_specifier}.
 @end table
 
 @section While playing
diff --git a/ffplay.c b/ffplay.c
index d6b17c2..f4f924d 100644
--- a/ffplay.c
+++ b/ffplay.c
@@ -92,6 +92,13 @@ const int program_birth_year = 2003;
 
 static int64_t sws_flags = SWS_BICUBIC;
 
+typedef struct {
+    const char *codec_name, *stream_specifier;
+} StreamCodecSpecifier;
+
+StreamCodecSpecifier *stream_codec_specifiers = NULL;
+int                nb_stream_codec_specifiers = 0;
+
 typedef struct MyAVPacketList {
     AVPacket pkt;
     struct MyAVPacketList *next;
@@ -299,9 +306,6 @@ static int loop = 1;
 static int framedrop = -1;
 static int infinite_buffer = -1;
 static enum ShowMode show_mode = SHOW_MODE_NONE;
-static const char *audio_codec_name;
-static const char *subtitle_codec_name;
-static const char *video_codec_name;
 static int rdftspeed = 20;
 #if CONFIG_AVFILTER
 static char *vfilters = NULL;
@@ -2302,6 +2306,7 @@ static int stream_component_open(VideoState *is, int stream_index)
     AVCodec *codec;
     AVDictionary *opts;
     AVDictionaryEntry *t = NULL;
+    int i, ret;
 
     if (stream_index < 0 || stream_index >= ic->nb_streams)
         return -1;
@@ -2310,9 +2315,24 @@ static int stream_component_open(VideoState *is, int stream_index)
     codec = avcodec_find_decoder(avctx->codec_id);
 
     switch(avctx->codec_type){
-        case AVMEDIA_TYPE_AUDIO   : is->last_audio_stream    = stream_index; if(audio_codec_name   ) codec= avcodec_find_decoder_by_name(   audio_codec_name); break;
-        case AVMEDIA_TYPE_SUBTITLE: is->last_subtitle_stream = stream_index; if(subtitle_codec_name) codec= avcodec_find_decoder_by_name(subtitle_codec_name); break;
-        case AVMEDIA_TYPE_VIDEO   : is->last_video_stream    = stream_index; if(video_codec_name   ) codec= avcodec_find_decoder_by_name(   video_codec_name); break;
+        case AVMEDIA_TYPE_AUDIO   : is->last_audio_stream    = stream_index;
+        case AVMEDIA_TYPE_SUBTITLE: is->last_subtitle_stream = stream_index;
+        case AVMEDIA_TYPE_VIDEO   : is->last_video_stream    = stream_index;
+    }
+
+    for (i = 0; i < nb_stream_codec_specifiers; i++) {
+        ret = avformat_match_stream_specifier(ic, ic->streams[stream_index],
+                                              stream_codec_specifiers[i].stream_specifier);
+        if (ret > 0) {
+            codec = avcodec_find_decoder_by_name(stream_codec_specifiers[i].codec_name);
+            avctx->codec_id = codec->id;
+            break;
+        }
+        if (ret < 0) {
+            fprintf(stderr, "Invalid stream specifier '%s' was specified\n",
+                    stream_codec_specifiers[i].stream_specifier);
+            return AVERROR(EINVAL);
+        }
     }
     if (!codec)
         return -1;
@@ -3149,11 +3169,21 @@ static void opt_input_file(void *optctx, const char *filename)
 
 static int opt_codec(void *o, const char *opt, const char *arg)
 {
-    switch(opt[strlen(opt)-1]){
-    case 'a' :    audio_codec_name = arg; break;
-    case 's' : subtitle_codec_name = arg; break;
-    case 'v' :    video_codec_name = arg; break;
+    const char *specifier = strchr(opt, ':');
+    if (!specifier) {
+        fprintf(stderr, "No stream specifier was specified in option name '%s'\n", opt);
+        return AVERROR(EINVAL);
     }
+    specifier++;
+
+    stream_codec_specifiers =
+        grow_array(stream_codec_specifiers, sizeof(StreamCodecSpecifier),
+                   &nb_stream_codec_specifiers, nb_stream_codec_specifiers+1);
+    if (!stream_codec_specifiers)
+        return AVERROR(ENOMEM);
+
+    stream_codec_specifiers[nb_stream_codec_specifiers-1].stream_specifier = specifier;
+    stream_codec_specifiers[nb_stream_codec_specifiers-1].codec_name       = arg;
     return 0;
 }
 
-- 
1.7.9.5