mpeg12enc: add seq_disp_ext option for deciding when to write a sequence_display_extension

Signed-off-by: Marton Balint <cus@passwd.hu>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

doc/encoders.texi

@@ -2042,6 +2042,30 @@ fastest.
 
 @end table
 
+@section mpeg2
+
+MPEG-2 video encoder.
+
+@subsection Options
+
+@table @option
+@item seq_disp_ext @var{integer}
+Specifies if the encoder should write a sequence_display_extension to the
+output.
+@table @option
+@item -1
+@itemx auto
+Decide automatically to write it or not (this is the default) by checking if
+the data to be written is different from the default or unspecified values.
+@item 0
+@itemx never
+Never write it.
+@item 1
+@itemx always
+Always write it.
+@end table
+@end table
+
 @section png
 
 PNG image encoder.

libavcodec/mpeg12enc.c

@@ -350,7 +350,7 @@ static void mpeg1_encode_sequence_header(MpegEncContext *s)
                                 s->avctx->color_trc != AVCOL_TRC_UNSPECIFIED ||
                                 s->avctx->colorspace != AVCOL_SPC_UNSPECIFIED);
 
-            if (use_seq_disp_ext) {
+            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, 0);                         // video_format: 0 is components
@@ -1123,6 +1123,10 @@ static const AVOption mpeg2_options[] = {
     COMMON_OPTS
     { "non_linear_quant", "Use nonlinear quantizer.",    OFFSET(q_scale_type),   AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, VE },
     { "alternate_scan",   "Enable alternate scantable.", OFFSET(alternate_scan), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, VE },
+    { "seq_disp_ext",     "Write sequence_display_extension blocks.", OFFSET(seq_disp_ext), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 1, VE, "seq_disp_ext" },
+    {     "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" },
     FF_MPV_COMMON_OPTS
     { NULL },
 };

libavcodec/mpegvideo.h

@@ -588,6 +588,7 @@ typedef struct MpegEncContext {
     int q_scale_type;
     int intra_vlc_format;
     int alternate_scan;
+    int seq_disp_ext;
     int repeat_first_field;
     int chroma_420_type;
     int chroma_format;

libavcodec/version.h

@@ -30,7 +30,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR 55
 #define LIBAVCODEC_VERSION_MINOR  66
-#define LIBAVCODEC_VERSION_MICRO 100
+#define LIBAVCODEC_VERSION_MICRO 101
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \