[FFmpeg-devel] [PATCH v3 2/2] avcodec/mpeg12enc: Support mpeg2 encoder profile with const options
Marton Balint
cus at passwd.hu
Fri May 1 18:02:35 EEST 2020
On Fri, 1 May 2020, lance.lmwang at gmail.com wrote:
> On Fri, May 01, 2020 at 03:22:32PM +0200, Marton Balint wrote:
>>
>>
>> On Fri, 1 May 2020, lance.lmwang at gmail.com wrote:
>>
>> > On Fri, May 01, 2020 at 12:32:44PM +0200, Marton Balint wrote:
>> > >
>> > >
>> > > On Fri, 1 May 2020, lance.lmwang at gmail.com wrote:
>> > >
>> > > > On Sat, Apr 04, 2020 at 08:25:31AM +0800, lance.lmwang at gmail.com wrote:
>> > > > > From: Limin Wang <lance.lmwang at gmail.com>
>> > > > > > > Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
>> > > > > ---
>> > > > > doc/encoders.texi | 8 ++++++++
>> > > > > libavcodec/mpeg12enc.c | 22 +++++++++++++++++-----
>> > > > > libavcodec/mpegvideo.h | 1 +
>> > > > > 3 files changed, 26 insertions(+), 5 deletions(-)
>> > > > > > > diff --git a/doc/encoders.texi b/doc/encoders.texi
>> > > > > index e23b6b3..5022b94 100644
>> > > > > --- a/doc/encoders.texi
>> > > > > +++ b/doc/encoders.texi
>> > > > > @@ -2753,6 +2753,14 @@ 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).
>> > > > > + at item profile @var{integer}
>> > > > > +Select the mpeg2 profile to encode, possible values:
>> > > > > + at table @samp
>> > > > > + at item 422
>> > > > > + at item high
>> > > > > + at item main
>> > > > > + at item simple
>> > > > > + at end table
>> > > > > @end table
>> > > > > > > @section png
>> > > > > diff --git a/libavcodec/mpeg12enc.c b/libavcodec/mpeg12enc.c
>> > > > > index 643ba81..9fe0c8b 100644
>> > > > > --- a/libavcodec/mpeg12enc.c
>> > > > > +++ b/libavcodec/mpeg12enc.c
>> > > > > @@ -156,23 +156,30 @@ static av_cold int encode_init(AVCodecContext *avctx)
>> > > > > }
>> > > > > }
>> > > > > > > - if (avctx->profile == FF_PROFILE_UNKNOWN) {
>> > > > > + if (s->profile == FF_PROFILE_UNKNOWN)
>> > > > > + s->profile = avctx->profile;
>> > > > > +
>> > > > > + if (s->profile == FF_PROFILE_UNKNOWN) {
>> > > > > if (avctx->level != FF_LEVEL_UNKNOWN) {
>> > > > > av_log(avctx, AV_LOG_ERROR, "Set profile and level\n");
>> > > > > return -1;
>> > > > > }
>> > > > > /* Main or 4:2:2 */
>> > > > > avctx->profile = s->chroma_format == CHROMA_420 ? FF_PROFILE_MPEG2_MAIN : FF_PROFILE_MPEG2_422;
>> > > > > + s->profile = s->chroma_format == CHROMA_420 ? FF_PROFILE_MPEG2_MAIN : FF_PROFILE_MPEG2_422;
>> > > > > + } else if (s->profile < FF_PROFILE_MPEG2_422) {
>> > > > > + av_log(avctx, AV_LOG_ERROR, "Invalid mpeg2 profile set\n");
>> > > > > + return -1;
>> > > > > }
>> > > > > > > if (avctx->level == FF_LEVEL_UNKNOWN) {
>> > > > > - if (avctx->profile == FF_PROFILE_MPEG2_422) { /* 4:2:2 */
>> > > > > + if (s->profile == FF_PROFILE_MPEG2_422) { /* 4:2:2 */
>> > > > > if (avctx->width <= 720 && avctx->height <= 608)
>> > > > > avctx->level = 5; /* Main */
>> > > > > else
>> > > > > avctx->level = 2; /* High */
>> > > > > } else {
>> > > > > - if (avctx->profile != FF_PROFILE_MPEG2_HIGH && s->chroma_format != CHROMA_420) {
>> > > > > + if (s->profile != FF_PROFILE_MPEG2_HIGH && s->chroma_format != CHROMA_420) {
>> > > > > av_log(avctx, AV_LOG_ERROR,
>> > > > > "Only High(1) and 4:2:2(0) profiles support 4:2:2 color sampling\n");
>> > > > > return -1;
>> > > > > @@ -321,9 +328,9 @@ static void mpeg1_encode_sequence_header(MpegEncContext *s)
>> > > > > put_header(s, EXT_START_CODE);
>> > > > > put_bits(&s->pb, 4, 1); // seq ext
>> > > > > > > - put_bits(&s->pb, 1, s->avctx->profile ==
>> > > FF_PROFILE_MPEG2_422); // escx 1 for 4:2:2 profile
>> > > > > + put_bits(&s->pb, 1, s->profile == FF_PROFILE_MPEG2_422); // escx 1 for 4:2:2 profile
>> > > > > > > - put_bits(&s->pb, 3, s->avctx->profile); //
>> > > profile
>> > > > > + put_bits(&s->pb, 3, s->profile); // profile
>> > > > > put_bits(&s->pb, 4, s->avctx->level); // level
>> > > > > > > put_bits(&s->pb, 1, s->progressive_sequence);
>> > > > > @@ -1165,6 +1172,11 @@ static const AVOption mpeg2_options[] = {
>> > > > > { "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" },
>> > > > > + { "profile", "Set the profile", OFFSET(profile), AV_OPT_TYPE_INT,{ .i64 = FF_PROFILE_UNKNOWN }, FF_PROFILE_UNKNOWN, FF_PROFILE_MPEG2_SIMPLE, VE, "profile" },
>> > > > > + { "422", "", 0, AV_OPT_TYPE_CONST,{ .i64 = FF_PROFILE_MPEG2_422 }, 0, 0, VE, "profile" },
>> > > > > + { "high", "", 0, AV_OPT_TYPE_CONST,{ .i64 = FF_PROFILE_MPEG2_HIGH }, 0, 0, VE, "profile" },
>> > > > > + { "main", "", 0, AV_OPT_TYPE_CONST,{ .i64 = FF_PROFILE_MPEG2_MAIN }, 0, 0, VE, "profile" },
>> > > > > + { "simple", "", 0, AV_OPT_TYPE_CONST,{ .i64 = FF_PROFILE_MPEG2_SIMPLE }, 0, 0, VE, "profile" },
>> > > > > FF_MPV_COMMON_OPTS
>> > > > > { NULL },
>> > > > > };
>> > > > > diff --git a/libavcodec/mpegvideo.h b/libavcodec/mpegvideo.h
>> > > > > index 29e692f..cee423e 100644
>> > > > > --- a/libavcodec/mpegvideo.h
>> > > > > +++ b/libavcodec/mpegvideo.h
>> > > > > @@ -456,6 +456,7 @@ typedef struct MpegEncContext {
>> > > > > int progressive_sequence;
>> > > > > int mpeg_f_code[2][2];
>> > > > > int a53_cc;
>> > > > > + int profile;
>> > > > > > > // picture structure defines are loaded from
>> > > mpegutils.h
>> > > > > int picture_structure;
>> > > > > -- > > 2.9.5
>> > > > > > > will apply the patch set.
>> > >
>> > > Hold on, this patch does not seem right. Is 422 as a named constant even
>> > > works?
>> >
>> > No problem, I'm waiting for comments still, what's the problem for 422? Below is my testing result:
>> >
>> > $ ./ffmpeg -y -f lavfi -i testsrc=duration=1 -c:v mpeg2video -profile:v 422 a.ts
>> > $ mediainfo a.ts
>> > ...
>> > Format : MPEG Video
>> > Format version : Version 2
>> > Format profile : 4:2:2 at Main
>> > Format settings, BVOP : No
>> > ...
>>
>> Okay, it seems to work yet I think it is not very good practice to use
>> constants which can be also parsed as integers.
>
> Yeah, now I understand your question for the 422 now.
>
>>
>> In general about the patch. Is it decided that we should move away from
>> using avctx->profile and use codec specific profiles? Because there are
>> quite a number of available profiles which simply use avctx for other
>> codecs.
>>
>> Also it would be inconsistent if for some codecs avctx->profile had
>> priority, where for other codecs, the priv_context->profile. DNXHD comes to
>> mind.
>
> At first, I have considered to add mpeg2_xxx in libavcodec/options_table.c,
> like the main10 is used by HEVC, so I think it's misleading to add mpeg2_main10.
> Then I notice x264 and some other code are using private profile for this, so
> I try to follow the same way.
>
>>
>> So until these are decided, I'd rather not add local profile options and I
>> think it is better to add the named constants with some prefix (mpeg2) to
>> libavcodec/options_table.c, to follow the existing pattern.
>
> As you prefer to change in global, I will update the patch to use global way
> with prefix if no other developer's comments.
>
>>
>> On a side note, the patch tries to reject invalid profiles, but does not
>> seem to do a very good job. MPEG2 profiles can only be 0..7, nothing else is
>> allowed. I wonder if generic code should reject invalid avctx->profiles?
>> After all, it is supposed to know the list of the allowed codec profiles,
>> but maybe for some formats limiting avctx->profile to the list is too
>> limiting?
>
> Yes, with codecs profile, we can check the valid of profile, but we can't check
> it with global profile.
I mean even for global avctx->profile the generic could could check if the
value is in AVCodecDescriptor->profiles. This is not done at the moment.
Regards,
Marton
More information about the ffmpeg-devel
mailing list