mxf: export ff_mxf_get_samples_per_frame to lavf

Reviewed-by: Tomas Härdin <tomas.hardin@codemill.se>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 29 insertions, 0 deletions

diff --git a/libavformat/mxf.c b/libavformat/mxf.c
index 224ade5d23..7230444b5f 100644
--- a/libavformat/mxf.c
+++ b/libavformat/mxf.c
@@ -106,3 +106,32 @@ int ff_mxf_decode_pixel_layout(const char pixel_layout[16], enum PixelFormat *pi
 
     return -1;
 }
+
+static const MXFSamplesPerFrame mxf_samples_per_frames[] = {
+    { { 1001, 24000 }, { 2002, 0,    0,    0,    0,    0 } }, // FILM 23.976
+    { { 1, 24},        { 2000, 0,    0,    0,    0,    0 } }, // FILM 24
+    { { 1001, 30000 }, { 1602, 1601, 1602, 1601, 1602, 0 } }, // NTSC 29.97
+    { { 1001, 60000 }, { 801,  801,  801,  801,  800,  0 } }, // NTSC 59.94
+    { { 1, 25 },       { 1920, 0,    0,    0,    0,    0 } }, // PAL 25
+    { { 1, 50 },       { 960,  0,    0,    0,    0,    0 } }, // PAL 50
+};
+
+const MXFSamplesPerFrame *ff_mxf_get_samples_per_frame(AVFormatContext *s, AVRational time_base)
+{
+    int i;
+    for (i = 0; i < FF_ARRAY_ELEMS(mxf_samples_per_frames); i++) {
+        if (!av_cmp_q(mxf_samples_per_frames[i].time_base, time_base))
+            return &mxf_samples_per_frames[i];
+    }
+
+    // Find closest container time base for approximative codec time base like 1/29.97, 1/30, ...
+    for (i = 0; i < FF_ARRAY_ELEMS(mxf_samples_per_frames); i++) {
+        if (fabs(av_q2d(mxf_samples_per_frames[i].time_base) - av_q2d(time_base)) < 0.0001) {
+            av_log(s, AV_LOG_WARNING, "%d/%d input time base matched %d/%d container time base\n",
+                   time_base.num, time_base.den,
+                   mxf_samples_per_frames[i].time_base.num, mxf_samples_per_frames[i].time_base.den);
+            return &mxf_samples_per_frames[i];
+        }
+    }
+    return NULL;
+}