add avcodec_get_context_defaults2() / avcodec_alloc_context2() which take CodecType as an additional parameter

also mark them as NOT part of the public API yet, so we can change their argument to CodecID if we decide to do so

Originally committed as revision 8283 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/avcodec.h

@@ -2631,6 +2631,10 @@ void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
  */
 void avcodec_get_context_defaults(AVCodecContext *s);
 
+/** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
+ *  we WILL change its arguments and name a few times! */
+void avcodec_get_context_defaults2(AVCodecContext *s, enum CodecType);
+
 /**
  * Allocates an AVCodecContext and sets its fields to default values.  The
  * resulting struct can be deallocated by simply calling av_free().
@@ -2640,6 +2644,10 @@ void avcodec_get_context_defaults(AVCodecContext *s);
  */
 AVCodecContext *avcodec_alloc_context(void);
 
+/** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
+ *  we WILL change its arguments and name a few times! */
+AVCodecContext *avcodec_alloc_context2(enum CodecType);
+
 /**
  * Sets the fields of the given AVFrame to default values.
  *

libavcodec/utils.c

@@ -731,12 +731,19 @@ static const AVOption options[]={
 
 static AVClass av_codec_context_class = { "AVCodecContext", context_to_name, options };
 
-void avcodec_get_context_defaults(AVCodecContext *s){
+void avcodec_get_context_defaults2(AVCodecContext *s, enum CodecType codec_type){
+    int flags=0;
     memset(s, 0, sizeof(AVCodecContext));
 
     s->av_class= &av_codec_context_class;
 
-    av_opt_set_defaults(s);
+    if(codec_type == CODEC_TYPE_AUDIO)
+        flags= AV_OPT_FLAG_AUDIO_PARAM;
+    else if(codec_type == CODEC_TYPE_VIDEO)
+        flags= AV_OPT_FLAG_VIDEO_PARAM;
+    else if(codec_type == CODEC_TYPE_SUBTITLE)
+        flags= AV_OPT_FLAG_SUBTITLE_PARAM;
+    av_opt_set_defaults2(s, flags, flags);
 
     s->rc_eq= "tex^qComp";
     s->time_base= (AVRational){0,1};
@@ -752,16 +759,24 @@ void avcodec_get_context_defaults(AVCodecContext *s){
     s->reget_buffer= avcodec_default_reget_buffer;
 }
 
-AVCodecContext *avcodec_alloc_context(void){
+AVCodecContext *avcodec_alloc_context2(enum CodecType codec_type){
     AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
 
     if(avctx==NULL) return NULL;
 
-    avcodec_get_context_defaults(avctx);
+    avcodec_get_context_defaults2(avctx, codec_type);
 
     return avctx;
 }
 
+void avcodec_get_context_defaults(AVCodecContext *s){
+    avcodec_get_context_defaults2(s, CODEC_TYPE_UNKNOWN);
+}
+
+AVCodecContext *avcodec_alloc_context(void){
+    return avcodec_alloc_context2(CODEC_TYPE_UNKNOWN);
+}
+
 void avcodec_get_frame_defaults(AVFrame *pic){
     memset(pic, 0, sizeof(AVFrame));