AVCodec.supported_framerates

Originally committed as revision 2821 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/avcodec.h

@@ -17,7 +17,7 @@ extern "C" {
 
 #define FFMPEG_VERSION_INT     0x000408
 #define FFMPEG_VERSION         "0.4.8"
-#define LIBAVCODEC_BUILD       4705
+#define LIBAVCODEC_BUILD       4706
 
 #define LIBAVCODEC_VERSION_INT FFMPEG_VERSION_INT
 #define LIBAVCODEC_VERSION     FFMPEG_VERSION
@@ -1605,6 +1605,7 @@ typedef struct AVCodec {
     const AVOption *options;
     struct AVCodec *next;
     void (*flush)(AVCodecContext *);
+    AVRational *supported_framerates; ///array of supported framerates, or NULL if any, array is terminated by {0,0}
 } AVCodec;
 
 /**

libavcodec/mpeg12.c

@@ -195,9 +195,11 @@ static int find_frame_rate_index(MpegEncContext *s){
     int64_t d;
 
     for(i=1;i<14;i++) {
+        int64_t n0= 1001LL/frame_rate_tab[i].den*frame_rate_tab[i].num*s->avctx->frame_rate_base;
+        int64_t n1= 1001LL*s->avctx->frame_rate;
         if(s->avctx->strict_std_compliance >= 0 && i>=9) break;
 
-        d = ABS(MPEG1_FRAME_RATE_BASE*(int64_t)s->avctx->frame_rate - frame_rate_tab[i]*(int64_t)s->avctx->frame_rate_base);
+        d = ABS(n0 - n1);
         if(d < dmin){
             dmin=d;
             s->frame_rate_index= i;
@@ -249,6 +251,8 @@ static void mpeg1_encode_sequence_header(MpegEncContext *s)
         if(aspect_ratio==0.0) aspect_ratio= 1.0; //pixel aspect 1:1 (VGA)
         
         if (s->current_picture.key_frame) {
+            AVRational framerate= frame_rate_tab[s->frame_rate_index];
+
             /* mpeg1 header repeated every gop */
             put_header(s, SEQ_START_CODE);
  
@@ -295,8 +299,8 @@ static void mpeg1_encode_sequence_header(MpegEncContext *s)
             constraint_parameter_flag= 
                 s->width <= 768 && s->height <= 576 && 
                 s->mb_width * s->mb_height <= 396 &&
-                s->mb_width * s->mb_height * frame_rate_tab[s->frame_rate_index] <= MPEG1_FRAME_RATE_BASE*396*25 &&
-                frame_rate_tab[s->frame_rate_index] <= MPEG1_FRAME_RATE_BASE*30 &&
+                s->mb_width * s->mb_height * framerate.num <= framerate.den*396*25 &&
+                framerate.num <= framerate.den*30 &&
                 vbv_buffer_size <= 20 &&
                 v <= 1856000/400 &&
                 s->codec_id == CODEC_ID_MPEG1VIDEO;
@@ -328,7 +332,7 @@ static void mpeg1_encode_sequence_header(MpegEncContext *s)
             put_bits(&s->pb, 1, 0); /* do drop frame */
             /* time code : we must convert from the real frame rate to a
                fake mpeg frame rate in case of low frame rate */
-            fps = (frame_rate_tab[s->frame_rate_index] + MPEG1_FRAME_RATE_BASE/2)/ MPEG1_FRAME_RATE_BASE;
+            fps = (framerate.num + framerate.den/2)/ framerate.den;
             time_code = s->current_picture_ptr->coded_picture_number;
 
             s->gop_picture_number = time_code;
@@ -1821,8 +1825,8 @@ static void mpeg_decode_sequence_extension(MpegEncContext *s)
     av_reduce(
         &s->avctx->frame_rate, 
         &s->avctx->frame_rate_base, 
-        frame_rate_tab[s->frame_rate_index] * (frame_rate_ext_n+1),
-        MPEG1_FRAME_RATE_BASE * (frame_rate_ext_d+1),
+        frame_rate_tab[s->frame_rate_index].num * (frame_rate_ext_n+1),
+        frame_rate_tab[s->frame_rate_index].den * (frame_rate_ext_d+1),
         1<<30);
 
     dprintf("sequence extension\n");
@@ -2366,7 +2370,7 @@ static int mpeg1_decode_sequence(AVCodecContext *avctx,
     avctx->sample_aspect_ratio= av_d2q(aspect, 255);
 
     s->frame_rate_index = get_bits(&s->gb, 4);
-    if (s->frame_rate_index == 0)
+    if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
         return -1;
     s->bit_rate = get_bits(&s->gb, 18) * 400;
     if (get_bits1(&s->gb) == 0) /* marker */
@@ -2386,13 +2390,8 @@ static int mpeg1_decode_sequence(AVCodecContext *avctx,
         avctx->has_b_frames= 1;
         avctx->width = width;
         avctx->height = height;
-        av_reduce(
-            &avctx->frame_rate, 
-            &avctx->frame_rate_base,
-            frame_rate_tab[s->frame_rate_index],
-            MPEG1_FRAME_RATE_BASE, //FIXME store in allready reduced form 
-            1<<30
-            );
+        avctx->frame_rate     = frame_rate_tab[s->frame_rate_index].num;
+        avctx->frame_rate_base= frame_rate_tab[s->frame_rate_index].den;
         avctx->bit_rate = s->bit_rate;
         
         if(avctx->xvmc_acceleration){
@@ -2818,6 +2817,7 @@ AVCodec mpeg1video_encoder = {
     encode_init,
     MPV_encode_picture,
     MPV_encode_end,
+    .supported_framerates= frame_rate_tab+1,
 };
 
 #ifdef CONFIG_RISKY
@@ -2830,6 +2830,7 @@ AVCodec mpeg2video_encoder = {
     encode_init,
     MPV_encode_picture,
     MPV_encode_end,
+    .supported_framerates= frame_rate_tab+1,
 };
 #endif
 #endif

libavcodec/mpeg12data.h

@@ -354,28 +354,24 @@ static const uint8_t mbMotionVectorTable[17][2] = {
 { 0xc, 10 },
 };
 
-#define MPEG1_FRAME_RATE_BASE 1001
-
-static const int frame_rate_tab[16] = {
-        0,        
-    24000,
-    24024,
-    25025,
-    30000,
-    30030,
-    50050,
-    60000,
-    60060,
+static const AVRational frame_rate_tab[] = {
+    {    0,    0},
+    {24000, 1001},
+    {   24,    1},
+    {   25,    1},
+    {30000, 1001},
+    {   30,    1},
+    {   50,    1},
+    {60000, 1001},
+    {   60,    1},
   // Xing's 15fps: (9)
-    15015,
+    {   15,    1},
   // libmpeg3's "Unofficial economy rates": (10-13)
-     5005,
-    10010,
-    12012,
-    15015,
-  // random, just to avoid segfault !never encode these
-    25025,
-    25025,
+    {    5,    1},
+    {   10,    1},
+    {   12,    1},
+    {   15,    1},
+    {    0,    0},
 };
 
 static const uint8_t non_linear_qscale[32] = {