[FFmpeg-devel] [PATCH] extract bit rate calculation into separate function
Robert Krüger
krueger
Wed Nov 11 09:28:37 CET 2009
On 10.11.2009, at 19:51, Michael Niedermayer wrote:
> On Tue, Nov 10, 2009 at 03:14:02PM +0100, Robert Kr?ger wrote:
>>
>> 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
>> + */
>
> this belongs in a header
>
moved to header avformat.h and changed name to av_codec_get_bitrate
because that seems to be the naming convention for exposed functions(?)
>
>> +int avcodec_get_bitrate(AVCodecContext *ctx)
>> +{
>> + int bitrate;
>> +
>> + switch(ctx->codec_type) {
>> + case CODEC_TYPE_VIDEO:
>> + bitrate = ctx->bit_rate;
>> + break;
>
> tabs
>
fixed
>
>> + 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;
>
> duplicate of av_get_bits_per_sample()
>
changed to use av_get_bits_per_sample
>
>> + 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;
>
> default:
>
fixed
Thanks for the review,
Robert
Index: libavcodec/utils.c
===================================================================
--- libavcodec/utils.c (revision 20510)
+++ libavcodec/utils.c (working copy)
@@ -741,6 +741,34 @@
return NULL;
}
+int av_codec_get_bitrate(AVCodecContext *ctx)
+{
+ int bitrate;
+ int bits_per_sample;
+
+ switch(ctx->codec_type) {
+ case CODEC_TYPE_VIDEO:
+ bitrate = ctx->bit_rate;
+ break;
+ case CODEC_TYPE_AUDIO:
+ bits_per_sample = av_get_bits_per_sample(ctx->codec_id);
+ bitrate = bits_per_sample ? ctx->sample_rate * ctx->channels *
bits_per_sample : ctx->bit_rate;
+ 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;
+ default:
+ break;
+ }
+ return bitrate;
+}
+
void avcodec_string(char *buf, int buf_size, AVCodecContext *enc,
int encode)
{
const char *codec_name;
@@ -813,7 +841,6 @@
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 +857,15 @@
", %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 +879,7 @@
snprintf(buf + strlen(buf), buf_size - strlen(buf),
", pass 2");
}
+ bitrate = av_codec_get_bitrate(enc);
if (bitrate != 0) {
snprintf(buf + strlen(buf), buf_size - strlen(buf),
", %d kb/s", bitrate / 1000);
Index: libavformat/avformat.h
===================================================================
--- libavformat/avformat.h (revision 20510)
+++ libavformat/avformat.h (working copy)
@@ -760,6 +760,14 @@
enum CodecID av_codec_get_id(const struct AVCodecTag * const *tags,
unsigned int tag);
unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags,
enum CodecID id);
+/**
+ * Calculates the bit rate of a stream
+ *
+ * @ctx AVCodecContext of the stream
+ * @return bit rate in bits per second
+ */
+int av_codec_get_bitrate(AVCodecContext *ctx);
+
/* media file input */
/**
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