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mpeg12enc: Use Closed Captions if available

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Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Mathieu Duponchelle 2019-02-08 23:10:12 +01:00 committed by Michael Niedermayer
parent def18ac43b
commit 6cfa173303
3 changed files with 37 additions and 0 deletions
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3
doc/encoders.texi
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@ -2574,6 +2574,9 @@ 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}.
@item a53cc @var{boolean}
Import closed captions (which must be ATSC compatible format) into output.
Default is 1 (on).
@end table
@section png

32
libavcodec/mpeg12enc.c
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@ -61,6 +61,8 @@ static uint32_t mpeg1_chr_dc_uni[512];
static uint8_t mpeg1_index_run[2][64];
static int8_t mpeg1_max_level[2][64];
#define A53_MAX_CC_COUNT 0x1f
static av_cold void init_uni_ac_vlc(RLTable *rl, uint8_t *uni_ac_vlc_len)
{
int i;
@ -544,6 +546,36 @@ void ff_mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
}
}
if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO && s->a53_cc) {
side_data = av_frame_get_side_data(s->current_picture_ptr->f,
AV_FRAME_DATA_A53_CC);
if (side_data) {
if (side_data->size <= A53_MAX_CC_COUNT * 3 && side_data->size % 3 == 0) {
int i = 0;
put_header (s, USER_START_CODE);
put_bits(&s->pb, 8, 'G'); // user_identifier
put_bits(&s->pb, 8, 'A');
put_bits(&s->pb, 8, '9');
put_bits(&s->pb, 8, '4');
put_bits(&s->pb, 8, 3); // user_data_type_code
put_bits(&s->pb, 8,
(side_data->size / 3 & A53_MAX_CC_COUNT) | 0x40); // flags, cc_count
put_bits(&s->pb, 8, 0xff); // em_data
for (i = 0; i < side_data->size; i++)
put_bits(&s->pb, 8, side_data->data[i]);
put_bits(&s->pb, 8, 0xff); // marker_bits
} else {
av_log(s->avctx, AV_LOG_WARNING,
"Warning Closed Caption size (%d) can not exceed 93 bytes "
"and must be a multiple of 3\n", side_data->size);
}
}
}
s->mb_y = 0;
ff_mpeg1_encode_slice_header(s);
}

2
libavcodec/mpegvideo.h
View File

@ -455,6 +455,7 @@ typedef struct MpegEncContext {
/* MPEG-2-specific - I wished not to have to support this mess. */
int progressive_sequence;
int mpeg_f_code[2][2];
int a53_cc;
// picture structure defines are loaded from mpegutils.h
int picture_structure;
@ -663,6 +664,7 @@ FF_MPV_OPT_CMP_FUNC, \
{"ps", "RTP payload size in bytes", FF_MPV_OFFSET(rtp_payload_size), AV_OPT_TYPE_INT, {.i64 = 0 }, INT_MIN, INT_MAX, FF_MPV_OPT_FLAGS }, \
{"mepc", "Motion estimation bitrate penalty compensation (1.0 = 256)", FF_MPV_OFFSET(me_penalty_compensation), AV_OPT_TYPE_INT, {.i64 = 256 }, INT_MIN, INT_MAX, FF_MPV_OPT_FLAGS }, \
{"mepre", "pre motion estimation", FF_MPV_OFFSET(me_pre), AV_OPT_TYPE_INT, {.i64 = 0 }, INT_MIN, INT_MAX, FF_MPV_OPT_FLAGS }, \
{"a53cc", "Use A53 Closed Captions (if available)", FF_MPV_OFFSET(a53_cc), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, FF_MPV_OPT_FLAGS }, \
extern const AVOption ff_mpv_generic_options[];