av_log() cleanup

 null pointer segfaults
 dont print redundant spam
 dont print prefix if reference==NULL
 class -> av_class
 dont copy AVClass to every object, its a waste of memory and not a good idea at all

Originally committed as revision 2841 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/avcodec.h

@@ -589,7 +589,7 @@ typedef struct AVCodecContext {
      * Info on struct for av_log
      * - set by avcodec_alloc_context
      */
-    AVClass class;
+    AVClass *av_class;
     /**
      * the average bitrate.
      * - encoding: set by user. unused for constant quantizer encoding

libavcodec/utils.c

@@ -342,9 +342,21 @@ enum PixelFormat avcodec_default_get_format(struct AVCodecContext *s, enum Pixel
     return fmt[0];
 }
 
+static const char* context_to_name(void* ptr) {
+    AVCodecContext *avc= ptr;
+
+    if(avc && avc->codec && avc->codec->name)
+        return avc->codec->name; 
+    else
+        return "NULL";
+}
+
+static AVClass av_codec_context_class = { "AVCodecContext", context_to_name };
+
 void avcodec_get_context_defaults(AVCodecContext *s){
     memset(s, 0, sizeof(AVCodecContext));
 
+    s->av_class= &av_codec_context_class;
     s->bit_rate= 800*1000;
     s->bit_rate_tolerance= s->bit_rate*10;
     s->qmin= 2;
@@ -386,16 +398,11 @@ void avcodec_get_context_defaults(AVCodecContext *s){
  * allocates a AVCodecContext and set it to defaults.
  * this can be deallocated by simply calling free() 
  */
-static const char* context_to_name(void* class_ptr) { return ((AVCodecContext*) class_ptr)->codec->name; }
-
-static AVClass av_codec_context_class = { "AVCodecContext", context_to_name };
-
 AVCodecContext *avcodec_alloc_context(void){
     AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
     
     if(avctx==NULL) return NULL;
     
-    avctx->class = av_codec_context_class;
     avcodec_get_context_defaults(avctx);
     
     return avctx;
@@ -840,23 +847,17 @@ int64_t av_rescale(int64_t a, int b, int c){
 
 /* av_log API */
 
-static const char* null_to_name(void* class_ptr) { return "NULL"; }
-
-static AVClass av_null_class = { "NULL", null_to_name };
-
 static int av_log_level = AV_LOG_DEBUG;
 
 static void av_log_default_callback(void* ptr, int level, const char* fmt, va_list vl)
 {
     static int print_prefix=1;
-    AVClass* avcl = ptr;
-    if(!avcl || !avcl->class_name)
-	avcl = &av_null_class;
+    AVClass* avc= ptr ? *(AVClass**)ptr : NULL;
     if(level>av_log_level)
 	return;
 #undef fprintf
-    if(print_prefix) {
-	    fprintf(stderr, "[%s:%s @ %p]", avcl->class_name, avcl->item_name(avcl), avcl);
+    if(print_prefix && avc) {
+	    fprintf(stderr, "[%s @ %p]", avc->item_name(ptr), avc);
     }
 #define fprintf please_use_av_log
         

libavformat/avformat.h

@@ -241,7 +241,7 @@ typedef struct AVStream {
 
 /* format I/O context */
 typedef struct AVFormatContext {
-    AVClass class; /* set by av_alloc_format_context */
+    AVClass *av_class; /* set by av_alloc_format_context */
     /* can only be iformat or oformat, not both at the same time */
     struct AVInputFormat *iformat;
     struct AVOutputFormat *oformat;

libavformat/utils.c

@@ -301,9 +301,9 @@ AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened)
  * open a media file from an IO stream. 'fmt' must be specified.
  */
 
-static const char* format_to_name(void* class_ptr)
+static const char* format_to_name(void* ptr)
 {
-    AVFormatContext* fc = (AVFormatContext*) class_ptr;
+    AVFormatContext* fc = (AVFormatContext*) ptr;
     if(fc->iformat) return fc->iformat->name;
     else if(fc->oformat) return fc->oformat->name;
     else return "NULL";
@@ -316,7 +316,7 @@ AVFormatContext *av_alloc_format_context(void)
     AVFormatContext *ic;
     ic = av_mallocz(sizeof(AVFormatContext));
     if (!ic) return ic;
-    ic->class = av_format_context_class;
+    ic->av_class = &av_format_context_class;
     return ic;
 }
 
@@ -1745,13 +1745,13 @@ void dump_format(AVFormatContext *ic,
     int i, flags;
     char buf[256];
 
-    av_log(ic, AV_LOG_DEBUG, "%s #%d, %s, %s '%s':\n", 
+    av_log(NULL, AV_LOG_DEBUG, "%s #%d, %s, %s '%s':\n", 
             is_output ? "Output" : "Input",
             index, 
             is_output ? ic->oformat->name : ic->iformat->name, 
             is_output ? "to" : "from", url);
     if (!is_output) {
-        av_log(ic, AV_LOG_DEBUG, "  Duration: ");
+        av_log(NULL, AV_LOG_DEBUG, "  Duration: ");
         if (ic->duration != AV_NOPTS_VALUE) {
             int hours, mins, secs, us;
             secs = ic->duration / AV_TIME_BASE;
@@ -1760,23 +1760,23 @@ void dump_format(AVFormatContext *ic,
             secs %= 60;
             hours = mins / 60;
             mins %= 60;
-            av_log(ic, AV_LOG_DEBUG, "%02d:%02d:%02d.%01d", hours, mins, secs, 
+            av_log(NULL, AV_LOG_DEBUG, "%02d:%02d:%02d.%01d", hours, mins, secs, 
                    (10 * us) / AV_TIME_BASE);
         } else {
-            av_log(ic, AV_LOG_DEBUG, "N/A");
+            av_log(NULL, AV_LOG_DEBUG, "N/A");
         }
-        av_log(ic, AV_LOG_DEBUG, ", bitrate: ");
+        av_log(NULL, AV_LOG_DEBUG, ", bitrate: ");
         if (ic->bit_rate) {
-            av_log(ic, AV_LOG_DEBUG,"%d kb/s", ic->bit_rate / 1000);
+            av_log(NULL, AV_LOG_DEBUG,"%d kb/s", ic->bit_rate / 1000);
         } else {
-            av_log(ic, AV_LOG_DEBUG, "N/A");
+            av_log(NULL, AV_LOG_DEBUG, "N/A");
         }
-        av_log(ic, AV_LOG_DEBUG, "\n");
+        av_log(NULL, AV_LOG_DEBUG, "\n");
     }
     for(i=0;i<ic->nb_streams;i++) {
         AVStream *st = ic->streams[i];
         avcodec_string(buf, sizeof(buf), &st->codec, is_output);
-        av_log(ic, AV_LOG_DEBUG, "  Stream #%d.%d", index, i);
+        av_log(NULL, AV_LOG_DEBUG, "  Stream #%d.%d", index, i);
         /* the pid is an important information, so we display it */
         /* XXX: add a generic system */
         if (is_output)
@@ -1784,9 +1784,9 @@ void dump_format(AVFormatContext *ic,
         else
             flags = ic->iformat->flags;
         if (flags & AVFMT_SHOW_IDS) {
-            av_log(ic, AV_LOG_DEBUG, "[0x%x]", st->id);
+            av_log(NULL, AV_LOG_DEBUG, "[0x%x]", st->id);
         }
-        av_log(ic, AV_LOG_DEBUG, ": %s\n", buf);
+        av_log(NULL, AV_LOG_DEBUG, ": %s\n", buf);
     }
 }