@@ -17,6 +17,7 @@ API changes, most recent first:

 2016-xx-xx - lavc 57.33.0 - avcodec.h

   xxxxxxx - Add AVCodecParameters and its related API.

+  xxxxxxx - Add av_get_audio_frame_duration2().

 2016-03-11 - xxxxxxx - lavf/lavc 57.28.101

   Add requirement to bitstream filtering API that returned packets with

@@ -5342,6 +5342,12 @@ int av_get_exact_bits_per_sample(enum AVCodecID codec_id);

  */

 int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);

+/**

+ * This function is the same as av_get_audio_frame_duration(), except it works

+ * with AVCodecParameters instead of an AVCodecContext.

+ */

+int av_get_audio_frame_duration2(AVCodecParameters *par, int frame_bytes);

+

 typedef struct AVBitStreamFilterContext {

     void *priv_data;

@@ -3145,21 +3145,16 @@ int av_get_bits_per_sample(enum AVCodecID codec_id)

     }

 }

-int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes)

+static int get_audio_frame_duration(enum AVCodecID id, int sr, int ch, int ba,

+                                    uint32_t tag, int bits_per_coded_sample, int64_t bitrate,

+                                    uint8_t * extradata, int frame_size, int frame_bytes)

 {

-    int id, sr, ch, ba, tag, bps;

-

-    id  = avctx->codec_id;

-    sr  = avctx->sample_rate;

-    ch  = avctx->channels;

-    ba  = avctx->block_align;

-    tag = avctx->codec_tag;

-    bps = av_get_exact_bits_per_sample(avctx->codec_id);

+    int bps = av_get_exact_bits_per_sample(id);

     /* codecs with an exact constant bits per sample */

     if (bps > 0 && ch > 0 && frame_bytes > 0 && ch < 32768 && bps < 32768)

         return (frame_bytes * 8LL) / (bps * ch);

-    bps = avctx->bits_per_coded_sample;

+    bps = bits_per_coded_sample;

     /* codecs with a fixed packet duration */

     switch (id) {

@@ -3245,7 +3240,7 @@ int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes)

                 return (frame_bytes - 8) * 2 / ch;

             case AV_CODEC_ID_ADPCM_THP:

             case AV_CODEC_ID_ADPCM_THP_LE:

-                if (avctx->extradata)

+                if (extradata)

                     return frame_bytes * 14 / (8 * ch);

                 break;

             case AV_CODEC_ID_ADPCM_XA:

@@ -3280,7 +3275,7 @@ int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes)

             if (ba > 0) {

                 /* calc from frame_bytes, channels, and block_align */

                 int blocks = frame_bytes / ba;

-                switch (avctx->codec_id) {

+                switch (id) {

                 case AV_CODEC_ID_ADPCM_IMA_WAV:

                     if (bps < 2 || bps > 5)

                         return 0;

@@ -3298,7 +3293,7 @@ int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes)

             if (bps > 0) {

                 /* calc from frame_bytes, channels, and bits_per_coded_sample */

-                switch (avctx->codec_id) {

+                switch (id) {

                 case AV_CODEC_ID_PCM_DVD:

                     if(bps<4)

                         return 0;

@@ -3315,19 +3310,37 @@ int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes)

     }

     /* Fall back on using frame_size */

-    if (avctx->frame_size > 1 && frame_bytes)

-        return avctx->frame_size;

+    if (frame_size > 1 && frame_bytes)

+        return frame_size;

     //For WMA we currently have no other means to calculate duration thus we

     //do it here by assuming CBR, which is true for all known cases.

-    if (avctx->bit_rate>0 && frame_bytes>0 && avctx->sample_rate>0 && avctx->block_align>1) {

-        if (avctx->codec_id == AV_CODEC_ID_WMAV1 || avctx->codec_id == AV_CODEC_ID_WMAV2)

-            return  (frame_bytes * 8LL * avctx->sample_rate) / avctx->bit_rate;

+    if (bitrate > 0 && frame_bytes > 0 && sr > 0 && ba > 1) {

+        if (id == AV_CODEC_ID_WMAV1 || id == AV_CODEC_ID_WMAV2)

+            return  (frame_bytes * 8LL * sr) / bitrate;

     }

     return 0;

 }

+int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes)

+{

+    return get_audio_frame_duration(avctx->codec_id, avctx->sample_rate,

+                                    avctx->channels, avctx->block_align,

+                                    avctx->codec_tag, avctx->bits_per_coded_sample,

+                                    avctx->bit_rate, avctx->extradata, avctx->frame_size,

+                                    frame_bytes);

+}

+

+int av_get_audio_frame_duration2(AVCodecParameters *par, int frame_bytes)

+{

+    return get_audio_frame_duration(par->codec_id, par->sample_rate,

+                                    par->channels, par->block_align,

+                                    par->codec_tag, par->bits_per_coded_sample,

+                                    par->bit_rate, par->extradata, par->frame_size,

+                                    frame_bytes);

+}

+

 #if !HAVE_THREADS

 int ff_thread_init(AVCodecContext *s)

 {