lavu: add av_get_alt_sample_fmt().

doc/APIchanges

@@ -13,6 +13,9 @@ libavutil:   2011-04-18
 
 API changes, most recent first:
 
+2011-xx-xx - xxxxxxx - lavu 51.28.1
+  Add av_get_alt_sample_fmt() to samplefmt.h.
+
 2011-11-03 - 96949da - lavu 51.23.0
   Add av_strcasecmp() and av_strncasecmp() to avstring.h.
 

libavutil/avutil.h

@@ -153,7 +153,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR 51
-#define LIBAVUTIL_VERSION_MINOR 27
+#define LIBAVUTIL_VERSION_MINOR 28
 #define LIBAVUTIL_VERSION_MICRO  0
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \

libavutil/samplefmt.c

@@ -26,20 +26,21 @@ typedef struct SampleFmtInfo {
     char name[4];
     int bits;
     int planar;
+    enum AVSampleFormat altform; ///< planar<->packed alternative form
 } SampleFmtInfo;
 
 /** this table gives more information about formats */
 static const SampleFmtInfo sample_fmt_info[AV_SAMPLE_FMT_NB] = {
-    [AV_SAMPLE_FMT_U8]   = { .name =   "u8", .bits =  8, .planar = 0 },
-    [AV_SAMPLE_FMT_S16]  = { .name =  "s16", .bits = 16, .planar = 0 },
-    [AV_SAMPLE_FMT_S32]  = { .name =  "s32", .bits = 32, .planar = 0 },
-    [AV_SAMPLE_FMT_FLT]  = { .name =  "flt", .bits = 32, .planar = 0 },
-    [AV_SAMPLE_FMT_DBL]  = { .name =  "dbl", .bits = 64, .planar = 0 },
-    [AV_SAMPLE_FMT_U8P]  = { .name =  "u8p", .bits =  8, .planar = 1 },
-    [AV_SAMPLE_FMT_S16P] = { .name = "s16p", .bits = 16, .planar = 1 },
-    [AV_SAMPLE_FMT_S32P] = { .name = "s32p", .bits = 32, .planar = 1 },
-    [AV_SAMPLE_FMT_FLTP] = { .name = "fltp", .bits = 32, .planar = 1 },
-    [AV_SAMPLE_FMT_DBLP] = { .name = "dblp", .bits = 64, .planar = 1 },
+    [AV_SAMPLE_FMT_U8]   = { .name =   "u8", .bits =  8, .planar = 0, .altform = AV_SAMPLE_FMT_U8P  },
+    [AV_SAMPLE_FMT_S16]  = { .name =  "s16", .bits = 16, .planar = 0, .altform = AV_SAMPLE_FMT_S16P },
+    [AV_SAMPLE_FMT_S32]  = { .name =  "s32", .bits = 32, .planar = 0, .altform = AV_SAMPLE_FMT_S32P },
+    [AV_SAMPLE_FMT_FLT]  = { .name =  "flt", .bits = 32, .planar = 0, .altform = AV_SAMPLE_FMT_FLTP },
+    [AV_SAMPLE_FMT_DBL]  = { .name =  "dbl", .bits = 64, .planar = 0, .altform = AV_SAMPLE_FMT_DBLP },
+    [AV_SAMPLE_FMT_U8P]  = { .name =  "u8p", .bits =  8, .planar = 1, .altform = AV_SAMPLE_FMT_U8   },
+    [AV_SAMPLE_FMT_S16P] = { .name = "s16p", .bits = 16, .planar = 1, .altform = AV_SAMPLE_FMT_S16  },
+    [AV_SAMPLE_FMT_S32P] = { .name = "s32p", .bits = 32, .planar = 1, .altform = AV_SAMPLE_FMT_S32  },
+    [AV_SAMPLE_FMT_FLTP] = { .name = "fltp", .bits = 32, .planar = 1, .altform = AV_SAMPLE_FMT_FLT  },
+    [AV_SAMPLE_FMT_DBLP] = { .name = "dblp", .bits = 64, .planar = 1, .altform = AV_SAMPLE_FMT_DBL  },
 };
 
 const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt)
@@ -59,6 +60,15 @@ enum AVSampleFormat av_get_sample_fmt(const char *name)
     return AV_SAMPLE_FMT_NONE;
 }
 
+enum AVSampleFormat av_get_alt_sample_fmt(enum AVSampleFormat sample_fmt, int planar)
+{
+    if (sample_fmt < 0 || sample_fmt >= AV_SAMPLE_FMT_NB)
+        return AV_SAMPLE_FMT_NONE;
+    if (sample_fmt_info[sample_fmt].planar == planar)
+        return sample_fmt;
+    return sample_fmt_info[sample_fmt].altform;
+}
+
 char *av_get_sample_fmt_string (char *buf, int buf_size, enum AVSampleFormat sample_fmt)
 {
     /* print header */

libavutil/samplefmt.h

@@ -53,6 +53,14 @@ const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt);
  */
 enum AVSampleFormat av_get_sample_fmt(const char *name);
 
+/**
+ * Return the planar<->packed alternative form of the given sample format, or
+ * AV_SAMPLE_FMT_NONE on error. If the passed sample_fmt is already in the
+ * requested planar/packed format, the format returned is the same as the
+ * input.
+ */
+enum AVSampleFormat av_get_alt_sample_fmt(enum AVSampleFormat sample_fmt, int planar);
+
 /**
  * Generate a string corresponding to the sample format with
  * sample_fmt, or a header if sample_fmt is negative.