avcodec/mpeg12enc: add support for specifying video_format in the sequence_display_extension

In a recent commit the default was changed from 0 (component) to 5
(unspecified), however some standards require using 0. With this option, the
user will be able to do so.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Marton Balint <cus@passwd.hu>

doc/encoders.texi

@@ -2359,6 +2359,11 @@ Never write it.
 @itemx always
 Always write it.
 @end table
+@item video_format @var{integer}
+Specifies the video_format written into the sequence display extension
+indicating the source of the video pictures. The default is @samp{unspecified},
+can be @samp{component}, @samp{pal}, @samp{ntsc}, @samp{secam} or @samp{mac}.
+For maximum compatibility, use @samp{component}.
 @end table
 
 @section png

libavcodec/mpeg12enc.c

@@ -348,12 +348,13 @@ static void mpeg1_encode_sequence_header(MpegEncContext *s)
                                 height != s->height ||
                                 s->avctx->color_primaries != AVCOL_PRI_UNSPECIFIED ||
                                 s->avctx->color_trc != AVCOL_TRC_UNSPECIFIED ||
-                                s->avctx->colorspace != AVCOL_SPC_UNSPECIFIED);
+                                s->avctx->colorspace != AVCOL_SPC_UNSPECIFIED ||
+                                s->video_format != VIDEO_FORMAT_UNSPECIFIED);
 
             if (s->seq_disp_ext == 1 || (s->seq_disp_ext == -1 && use_seq_disp_ext)) {
                 put_header(s, EXT_START_CODE);
                 put_bits(&s->pb, 4, 2);                         // sequence display extension
-                put_bits(&s->pb, 3, 5);                         // video_format: 5 is unspecified
+                put_bits(&s->pb, 3, s->video_format);           // video_format
                 put_bits(&s->pb, 1, 1);                         // colour_description
                 put_bits(&s->pb, 8, s->avctx->color_primaries); // colour_primaries
                 put_bits(&s->pb, 8, s->avctx->color_trc);       // transfer_characteristics
@@ -1125,6 +1126,13 @@ static const AVOption mpeg2_options[] = {
     {     "auto",   NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = -1},  0, 0, VE, "seq_disp_ext" },
     {     "never",  NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = 0 },  0, 0, VE, "seq_disp_ext" },
     {     "always", NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = 1 },  0, 0, VE, "seq_disp_ext" },
+    { "video_format",     "Video_format in the sequence_display_extension indicating the source of the video.", OFFSET(video_format), AV_OPT_TYPE_INT, { .i64 = VIDEO_FORMAT_UNSPECIFIED }, 0, 7, VE, "video_format" },
+    {     "component",    NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = VIDEO_FORMAT_COMPONENT  },  0, 0, VE, "video_format" },
+    {     "pal",          NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = VIDEO_FORMAT_PAL        },  0, 0, VE, "video_format" },
+    {     "ntsc",         NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = VIDEO_FORMAT_NTSC       },  0, 0, VE, "video_format" },
+    {     "secam",        NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = VIDEO_FORMAT_SECAM      },  0, 0, VE, "video_format" },
+    {     "mac",          NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = VIDEO_FORMAT_MAC        },  0, 0, VE, "video_format" },
+    {     "unspecified",  NULL, 0, AV_OPT_TYPE_CONST,  {.i64 = VIDEO_FORMAT_UNSPECIFIED},  0, 0, VE, "video_format" },
     FF_MPV_COMMON_OPTS
     { NULL },
 };

libavcodec/mpegvideo.h

@@ -464,6 +464,13 @@ typedef struct MpegEncContext {
     int intra_vlc_format;
     int alternate_scan;
     int seq_disp_ext;
+    int video_format;
+#define VIDEO_FORMAT_COMPONENT   0
+#define VIDEO_FORMAT_PAL         1
+#define VIDEO_FORMAT_NTSC        2
+#define VIDEO_FORMAT_SECAM       3
+#define VIDEO_FORMAT_MAC         4
+#define VIDEO_FORMAT_UNSPECIFIED 5
     int repeat_first_field;
     int chroma_420_type;
     int chroma_format;

libavcodec/version.h

@@ -29,7 +29,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR  58
 #define LIBAVCODEC_VERSION_MINOR  11
-#define LIBAVCODEC_VERSION_MICRO 100
+#define LIBAVCODEC_VERSION_MICRO 101
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \