Add request_sample_fmt field to AVCodecContext.

This will allow audio decoders to support output of different sample formats
as a runtime option.

libavcodec/avcodec.h

@@ -2836,6 +2836,13 @@ typedef struct AVCodecContext {
      * - decoding: Set by libavcodec.
      */
     enum AVAudioServiceType audio_service_type;
+
+    /**
+     * Used to request a sample format from the decoder.
+     * - encoding: unused.
+     * - decoding: Set by user.
+     */
+    enum AVSampleFormat request_sample_fmt;
 } AVCodecContext;
 
 /**

libavcodec/options.c

@@ -441,6 +441,12 @@ static const AVOption options[]={
 {"em", "Emergency",          0, FF_OPT_TYPE_CONST, {.dbl = AV_AUDIO_SERVICE_TYPE_EMERGENCY },         INT_MIN, INT_MAX, A|E, "audio_service_type"},
 {"vo", "Voice Over",         0, FF_OPT_TYPE_CONST, {.dbl = AV_AUDIO_SERVICE_TYPE_VOICE_OVER },        INT_MIN, INT_MAX, A|E, "audio_service_type"},
 {"ka", "Karaoke",            0, FF_OPT_TYPE_CONST, {.dbl = AV_AUDIO_SERVICE_TYPE_KARAOKE },           INT_MIN, INT_MAX, A|E, "audio_service_type"},
+{"request_sample_fmt", NULL, OFFSET(request_sample_fmt), FF_OPT_TYPE_INT, {.dbl = AV_SAMPLE_FMT_NONE }, AV_SAMPLE_FMT_NONE, AV_SAMPLE_FMT_NB-1, A|D, "request_sample_fmt"},
+{"u8" , "8-bit unsigned integer", 0, FF_OPT_TYPE_CONST, {.dbl = AV_SAMPLE_FMT_U8  }, INT_MIN, INT_MAX, A|D, "request_sample_fmt"},
+{"s16", "16-bit signed integer",  0, FF_OPT_TYPE_CONST, {.dbl = AV_SAMPLE_FMT_S16 }, INT_MIN, INT_MAX, A|D, "request_sample_fmt"},
+{"s32", "32-bit signed integer",  0, FF_OPT_TYPE_CONST, {.dbl = AV_SAMPLE_FMT_S32 }, INT_MIN, INT_MAX, A|D, "request_sample_fmt"},
+{"flt", "32-bit float",           0, FF_OPT_TYPE_CONST, {.dbl = AV_SAMPLE_FMT_FLT }, INT_MIN, INT_MAX, A|D, "request_sample_fmt"},
+{"dbl", "64-bit double",          0, FF_OPT_TYPE_CONST, {.dbl = AV_SAMPLE_FMT_DBL }, INT_MIN, INT_MAX, A|D, "request_sample_fmt"},
 {NULL},
 };
 

libavcodec/version.h

@@ -21,7 +21,7 @@
 #define AVCODEC_VERSION_H
 
 #define LIBAVCODEC_VERSION_MAJOR 53
-#define LIBAVCODEC_VERSION_MINOR  3
+#define LIBAVCODEC_VERSION_MINOR  4
 #define LIBAVCODEC_VERSION_MICRO  0
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \