[FFmpeg-devel] [PATCH] extract bit rate calculation into separate function

[Robert Krüger]

Hi,

this patch extracts the bit rate calculation into a new function so  
applications using libav like ffprobe do not have to duplicate this.

Regression tests passed. At least I think they did because they  
completed without a final error message.

I hope this meets your requirements. If not, please let me know what I  
should change.

Thanks and regards,

Robert


Index: libavcodec/utils.c
===================================================================
--- libavcodec/utils.c	(revision 20498)
+++ libavcodec/utils.c	(working copy)
@@ -741,6 +741,74 @@
      return NULL;
  }

+/**
+ * Calculates the bit rate of a stream
+ *
+ * @ctx AVCodecContext of the stream
+ * @return bit rate in bits per second
+ */
+int avcodec_get_bitrate(AVCodecContext *ctx)
+{
+    int bitrate;
+
+    switch(ctx->codec_type) {
+    case CODEC_TYPE_VIDEO:
+  	    bitrate = ctx->bit_rate;
+    	break;
+    case CODEC_TYPE_AUDIO:
+        /* for PCM codecs, compute bitrate directly */
+        switch(ctx->codec_id) {
+        case CODEC_ID_PCM_F64BE:
+        case CODEC_ID_PCM_F64LE:
+            bitrate = ctx->sample_rate * ctx->channels * 64;
+            break;
+        case CODEC_ID_PCM_S32LE:
+        case CODEC_ID_PCM_S32BE:
+        case CODEC_ID_PCM_U32LE:
+        case CODEC_ID_PCM_U32BE:
+        case CODEC_ID_PCM_F32BE:
+        case CODEC_ID_PCM_F32LE:
+            bitrate = ctx->sample_rate * ctx->channels * 32;
+            break;
+        case CODEC_ID_PCM_S24LE:
+        case CODEC_ID_PCM_S24BE:
+        case CODEC_ID_PCM_U24LE:
+        case CODEC_ID_PCM_U24BE:
+        case CODEC_ID_PCM_S24DAUD:
+            bitrate = ctx->sample_rate * ctx->channels * 24;
+            break;
+        case CODEC_ID_PCM_S16LE:
+        case CODEC_ID_PCM_S16BE:
+        case CODEC_ID_PCM_S16LE_PLANAR:
+        case CODEC_ID_PCM_U16LE:
+        case CODEC_ID_PCM_U16BE:
+            bitrate = ctx->sample_rate * ctx->channels * 16;
+            break;
+        case CODEC_ID_PCM_S8:
+        case CODEC_ID_PCM_U8:
+        case CODEC_ID_PCM_ALAW:
+        case CODEC_ID_PCM_MULAW:
+        case CODEC_ID_PCM_ZORK:
+            bitrate = ctx->sample_rate * ctx->channels * 8;
+            break;
+        default:
+            bitrate = ctx->bit_rate;
+            break;
+        }
+        break;
+        case CODEC_TYPE_DATA:
+            bitrate = ctx->bit_rate;
+            break;
+        case CODEC_TYPE_SUBTITLE:
+            bitrate = ctx->bit_rate;
+            break;
+        case CODEC_TYPE_ATTACHMENT:
+            bitrate = ctx->bit_rate;
+            break;
+    }
+    return bitrate;
+}
+
  void avcodec_string(char *buf, int buf_size, AVCodecContext *enc,  
int encode)
  {
      const char *codec_name;
@@ -813,7 +881,6 @@
              snprintf(buf + strlen(buf), buf_size - strlen(buf),
                       ", q=%d-%d", enc->qmin, enc->qmax);
          }
-        bitrate = enc->bit_rate;
          break;
      case CODEC_TYPE_AUDIO:
          snprintf(buf, buf_size,
@@ -830,57 +897,15 @@
                       ", %s", avcodec_get_sample_fmt_name(enc- 
 >sample_fmt));
          }

-        /* for PCM codecs, compute bitrate directly */
-        switch(enc->codec_id) {
-        case CODEC_ID_PCM_F64BE:
-        case CODEC_ID_PCM_F64LE:
-            bitrate = enc->sample_rate * enc->channels * 64;
-            break;
-        case CODEC_ID_PCM_S32LE:
-        case CODEC_ID_PCM_S32BE:
-        case CODEC_ID_PCM_U32LE:
-        case CODEC_ID_PCM_U32BE:
-        case CODEC_ID_PCM_F32BE:
-        case CODEC_ID_PCM_F32LE:
-            bitrate = enc->sample_rate * enc->channels * 32;
-            break;
-        case CODEC_ID_PCM_S24LE:
-        case CODEC_ID_PCM_S24BE:
-        case CODEC_ID_PCM_U24LE:
-        case CODEC_ID_PCM_U24BE:
-        case CODEC_ID_PCM_S24DAUD:
-            bitrate = enc->sample_rate * enc->channels * 24;
-            break;
-        case CODEC_ID_PCM_S16LE:
-        case CODEC_ID_PCM_S16BE:
-        case CODEC_ID_PCM_S16LE_PLANAR:
-        case CODEC_ID_PCM_U16LE:
-        case CODEC_ID_PCM_U16BE:
-            bitrate = enc->sample_rate * enc->channels * 16;
-            break;
-        case CODEC_ID_PCM_S8:
-        case CODEC_ID_PCM_U8:
-        case CODEC_ID_PCM_ALAW:
-        case CODEC_ID_PCM_MULAW:
-        case CODEC_ID_PCM_ZORK:
-            bitrate = enc->sample_rate * enc->channels * 8;
-            break;
-        default:
-            bitrate = enc->bit_rate;
-            break;
-        }
          break;
      case CODEC_TYPE_DATA:
          snprintf(buf, buf_size, "Data: %s", codec_name);
-        bitrate = enc->bit_rate;
          break;
      case CODEC_TYPE_SUBTITLE:
          snprintf(buf, buf_size, "Subtitle: %s", codec_name);
-        bitrate = enc->bit_rate;
          break;
      case CODEC_TYPE_ATTACHMENT:
          snprintf(buf, buf_size, "Attachment: %s", codec_name);
-        bitrate = enc->bit_rate;
          break;
      default:
          snprintf(buf, buf_size, "Invalid Codec type %d", enc- 
 >codec_type);
@@ -894,6 +919,7 @@
              snprintf(buf + strlen(buf), buf_size - strlen(buf),
                       ", pass 2");
      }
+    bitrate = avcodec_get_bitrate(enc);
      if (bitrate != 0) {
          snprintf(buf + strlen(buf), buf_size - strlen(buf),
                   ", %d kb/s", bitrate / 1000);