Message ID | 20190207200316.4357-1-mathieu@centricular.com |
---|---|
State | Superseded |
Headers | show |
On Thu, Feb 07, 2019 at 09:03:16PM +0100, Mathieu Duponchelle wrote: > --- > doc/encoders.texi | 3 +++ > libavcodec/mpeg12enc.c | 31 +++++++++++++++++++++++++++++++ > libavcodec/mpegvideo.h | 2 ++ > 3 files changed, 36 insertions(+) > > diff --git a/doc/encoders.texi b/doc/encoders.texi > index e86ae69cc5..a283b9fddf 100644 > --- a/doc/encoders.texi > +++ b/doc/encoders.texi > @@ -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 > diff --git a/libavcodec/mpeg12enc.c b/libavcodec/mpeg12enc.c > index d0b458e34b..15a3db9e6d 100644 > --- a/libavcodec/mpeg12enc.c > +++ b/libavcodec/mpeg12enc.c > @@ -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 +546,35 @@ 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) { > + 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 what if size is not a multiple of 3 ? [...]
On 2/8/19 11:58 AM, Michael Niedermayer wrote:
> what if size is not a multiple of 3 ?
Good point, more bytes will be written than advertised. Do you reckon
the input should be straight up refused? The other solution is to warn then
iterate over side_data->size rounded down to the closest 3 multiple.
> On Feb 8, 2019, at 9:47 AM, Mathieu Duponchelle <mathieu@centricular.com> wrote: > > On 2/8/19 11:58 AM, Michael Niedermayer wrote: >> what if size is not a multiple of 3 ? > > Good point, more bytes will be written than advertised. Do you reckon > the input should be straight up refused? The other solution is to warn then > iterate over side_data->size rounded down to the closest 3 multiple. Yeah, so there are all sorts of ways the content could be screwed up and I don’t think we want to get into the business of having every encoder module try to validate it. That said, a quick length check is reasonable to avoid a possible buffer overflow, so I would just write a log message and throw the entire array on the floor. Devin --- Devin Heitmueller - LTN Global Communications dheitmueller@ltnglobal.com
diff --git a/doc/encoders.texi b/doc/encoders.texi index e86ae69cc5..a283b9fddf 100644 --- a/doc/encoders.texi +++ b/doc/encoders.texi @@ -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 diff --git a/libavcodec/mpeg12enc.c b/libavcodec/mpeg12enc.c index d0b458e34b..15a3db9e6d 100644 --- a/libavcodec/mpeg12enc.c +++ b/libavcodec/mpeg12enc.c @@ -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 +546,35 @@ 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) { + 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 can not exceed 93 bytes\n"); + } + } + } + s->mb_y = 0; ff_mpeg1_encode_slice_header(s); } diff --git a/libavcodec/mpegvideo.h b/libavcodec/mpegvideo.h index bbc6b5646a..3e52f98390 100644 --- a/libavcodec/mpegvideo.h +++ b/libavcodec/mpegvideo.h @@ -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[];