[FFmpeg-devel] [PATCH] Add MPL2 subtitles demuxer and decoder.

Stefano Sabatini stefasab at gmail.com
Sat Dec 29 12:45:18 CET 2012


On date Thursday 2012-12-27 15:05:04 +0100, Clément Bœsch encoded:
> ---
>  Changelog                |   1 +
>  doc/general.texi         |   1 +
>  libavcodec/Makefile      |   1 +
>  libavcodec/allcodecs.c   |   1 +
>  libavcodec/avcodec.h     |   1 +
>  libavcodec/mpl2dec.c     |  94 +++++++++++++++++++++++++++++
>  libavcodec/version.h     |   2 +-
>  libavformat/Makefile     |   1 +
>  libavformat/allformats.c |   1 +
>  libavformat/mpl2dec.c    | 150 +++++++++++++++++++++++++++++++++++++++++++++++
>  libavformat/version.h    |   4 +-
>  tests/fate/subtitles.mak |   3 +
>  tests/ref/fate/sub-mpl2  |   1 +
>  13 files changed, 258 insertions(+), 3 deletions(-)
>  create mode 100644 libavcodec/mpl2dec.c
>  create mode 100644 libavformat/mpl2dec.c
>  create mode 100644 tests/ref/fate/sub-mpl2
> 
> diff --git a/Changelog b/Changelog
> index 9eec45c..e8b2ecf 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -50,6 +50,7 @@ version <next>:
>  - documentation split into per-component manuals
>  - pp (postproc) filter ported from MPlayer
>  - NIST Sphere demuxer
> +- MPL2 subtitles demuxer and decoder
>  
>  
>  version 1.0:
> diff --git a/doc/general.texi b/doc/general.texi
> index 5dc1954..472ceac 100644
> --- a/doc/general.texi
> +++ b/doc/general.texi
> @@ -924,6 +924,7 @@ performance on systems without hardware floating point support).
>  @item DVD              @tab X @tab X @tab X @tab X
>  @item JACOsub          @tab X @tab X @tab   @tab X
>  @item MicroDVD         @tab X @tab X @tab   @tab X
> + at item MPL2             @tab   @tab X @tab   @tab X
>  @item PGS              @tab   @tab   @tab   @tab X
>  @item RealText         @tab   @tab X @tab   @tab X
>  @item SAMI             @tab   @tab X @tab   @tab X

Unrelated: I wonder if we should tackle this with some scripting and
avoid the need to update the file.

> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 1ca490c..54d1095 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -292,6 +292,7 @@ OBJS-$(CONFIG_MPEG2VIDEO_DECODER)      += mpeg12.o mpeg12data.o
>  OBJS-$(CONFIG_MPEG2VIDEO_ENCODER)      += mpeg12enc.o mpeg12.o          \
>                                            timecode.o
>  OBJS-$(CONFIG_MPEG4_VAAPI_HWACCEL)     += vaapi_mpeg4.o
> +OBJS-$(CONFIG_MPL2_DECODER)            += mpl2dec.o ass.o
>  OBJS-$(CONFIG_MSMPEG4V1_DECODER)       += msmpeg4.o msmpeg4data.o
>  OBJS-$(CONFIG_MSMPEG4V2_DECODER)       += msmpeg4.o msmpeg4data.o h263dec.o \
>                                            h263.o ituh263dec.o mpeg4videodec.o
> diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
> index edeb3fb..5ff1586 100644
> --- a/libavcodec/allcodecs.c
> +++ b/libavcodec/allcodecs.c
> @@ -429,6 +429,7 @@ void avcodec_register_all(void)
>      REGISTER_DECODER (JACOSUB, jacosub);
>      REGISTER_DECODER (MICRODVD, microdvd);
>      REGISTER_ENCDEC  (MOVTEXT, movtext);
> +    REGISTER_DECODER (MPL2, mpl2);
>      REGISTER_DECODER (PGSSUB, pgssub);
>      REGISTER_DECODER (REALTEXT, realtext);
>      REGISTER_DECODER (SAMI, sami);
> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
> index 11c50ca..5bec7cd 100644
> --- a/libavcodec/avcodec.h
> +++ b/libavcodec/avcodec.h
> @@ -466,6 +466,7 @@ enum AVCodecID {
>      AV_CODEC_ID_SUBVIEWER  = MKBETAG('S','u','b','V'),
>      AV_CODEC_ID_SUBRIP     = MKBETAG('S','R','i','p'),
>      AV_CODEC_ID_WEBVTT     = MKBETAG('W','V','T','T'),
> +    AV_CODEC_ID_MPL2       = MKBETAG('M','P','L','2'),
>  
>      /* other specific kind of codecs (generally used for attachments) */
>      AV_CODEC_ID_FIRST_UNKNOWN = 0x18000,           ///< A dummy ID pointing at the start of various fake codecs.
> diff --git a/libavcodec/mpl2dec.c b/libavcodec/mpl2dec.c
> new file mode 100644
> index 0000000..34c7d43
> --- /dev/null
> +++ b/libavcodec/mpl2dec.c
> @@ -0,0 +1,94 @@
> +/*
> + * Copyright (c) 2012 Clément Bœsch
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +/**
> + * @file
> + * MPL2 subtitles decoder

maybe mention a spec or some doc here, for example this one:
http://web.archive.org/web/20090328040233/http://napisy.ussbrowarek.org/mpl2-eng.html

> + */
> +
> +#include "avcodec.h"
> +#include "ass.h"
> +#include "libavutil/bprint.h"
> +
> +static int mpl2_event_to_ass(AVBPrint *buf, const char *p)
> +{
> +    if (*p == ' ')
> +        p++;
> +
> +    while (*p) {
> +        int got_style = 0;
> +
> +        while (*p && strchr("/\\_", *p)) {
> +            if      (*p == '/')  av_bprintf(buf, "{\\i1}");
> +            else if (*p == '\\') av_bprintf(buf, "{\\b1}");
> +            else if (*p == '_')  av_bprintf(buf, "{\\u1}");
> +            got_style = 1;
> +            p++;
> +        }
> +
> +        while (*p && *p != '|') {
> +            if (*p != '\r' && *p != '\n')
> +                av_bprint_chars(buf, *p, 1);
> +            p++;
> +        }
> +
> +        if (*p == '|') {
> +            if (got_style)
> +                av_bprintf(buf, "{\\r}");
> +            av_bprintf(buf, "\\N");
> +            p++;
> +        }
> +    }
> +
> +    av_bprintf(buf, "\r\n");
> +    return 0;
> +}
> +

> +static int mpl2_decode_frame(AVCodecContext *avctx, void *data,
> +                             int *got_sub_ptr, AVPacket *avpkt)
> +{
> +    AVBPrint buf;
> +    AVSubtitle *sub = data;
> +    const char *ptr = avpkt->data;
> +    const int ts_start     = av_rescale_q(avpkt->pts,      avctx->time_base, (AVRational){1,100});

> +    const int ts_duration  = avpkt->duration != -1 ?

is -1 allowed? I ask because I can't find it specified in avcodec.h.

> +                             av_rescale_q(avpkt->duration, avctx->time_base, (AVRational){1,100}) : -1;



> +
> +    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
> +    if (ptr && avpkt->size > 0 && *ptr && !mpl2_event_to_ass(&buf, ptr)) {
> +        if (!av_bprint_is_complete(&buf)) {
> +            av_bprint_finalize(&buf, NULL);
> +            return AVERROR(ENOMEM);
> +        }
> +        ff_ass_add_rect(sub, buf.str, ts_start, ts_duration, 0);
> +    }
> +    *got_sub_ptr = sub->num_rects > 0;
> +    av_bprint_finalize(&buf, NULL);
> +    return avpkt->size;
> +}
> +
> +AVCodec ff_mpl2_decoder = {
> +    .name           = "mpl2",
> +    .long_name      = NULL_IF_CONFIG_SMALL("MPL2 subtitle"),
> +    .type           = AVMEDIA_TYPE_SUBTITLE,
> +    .id             = AV_CODEC_ID_MPL2,
> +    .decode         = mpl2_decode_frame,
> +    .init           = ff_ass_subtitle_header_default,
> +};
> diff --git a/libavcodec/version.h b/libavcodec/version.h
> index 74c8360..32d3650 100644
> --- a/libavcodec/version.h
> +++ b/libavcodec/version.h
> @@ -29,7 +29,7 @@
>  #include "libavutil/avutil.h"
>  
>  #define LIBAVCODEC_VERSION_MAJOR 54
> -#define LIBAVCODEC_VERSION_MINOR 81
> +#define LIBAVCODEC_VERSION_MINOR 82
>  #define LIBAVCODEC_VERSION_MICRO 100
>  
>  #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index 587fa42..f699453 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -219,6 +219,7 @@ OBJS-$(CONFIG_MPEGTS_DEMUXER)            += mpegts.o isom.o
>  OBJS-$(CONFIG_MPEGTS_MUXER)              += mpegtsenc.o
>  OBJS-$(CONFIG_MPEGVIDEO_DEMUXER)         += mpegvideodec.o rawdec.o
>  OBJS-$(CONFIG_MPJPEG_MUXER)              += mpjpeg.o
> +OBJS-$(CONFIG_MPL2_DEMUXER)              += mpl2dec.o
>  OBJS-$(CONFIG_MSNWC_TCP_DEMUXER)         += msnwc_tcp.o
>  OBJS-$(CONFIG_MTV_DEMUXER)               += mtv.o
>  OBJS-$(CONFIG_MVI_DEMUXER)               += mvi.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index 6b4c27b..3cffb82 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -170,6 +170,7 @@ void av_register_all(void)
>      REGISTER_DEMUXER  (MPEGTSRAW, mpegtsraw);
>      REGISTER_DEMUXER  (MPEGVIDEO, mpegvideo);
>      REGISTER_MUXER    (MPJPEG, mpjpeg);
> +    REGISTER_DEMUXER  (MPL2, mpl2);
>      REGISTER_DEMUXER  (MSNWC_TCP, msnwc_tcp);
>      REGISTER_DEMUXER  (MTV, mtv);
>      REGISTER_DEMUXER  (MV, mv);
> diff --git a/libavformat/mpl2dec.c b/libavformat/mpl2dec.c
> new file mode 100644
> index 0000000..c5b0ab9
> --- /dev/null
> +++ b/libavformat/mpl2dec.c
> @@ -0,0 +1,150 @@
> +/*
> + * Copyright (c) 2012 Clément Bœsch
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +/**
> + * @file
> + * MPL2 subtitles format demuxer
> + */
> +
> +#include "avformat.h"
> +#include "internal.h"
> +#include "subtitles.h"
> +#include "libavutil/opt.h"
> +#include "libavutil/avstring.h"
> +#include "libavutil/bprint.h"
> +#include "libavutil/intreadwrite.h"
> +
> +typedef struct {
> +    FFDemuxSubtitlesQueue q;
> +} MPL2Context;
> +
> +static int mpl2_probe(AVProbeData *p)
> +{
> +    int i;
> +    char c;
> +    int64_t start, end;
> +    const unsigned char *ptr = p->buf;
> +    const unsigned char *ptr_end = ptr + p->buf_size;
> +
> +    for (i = 0; i < 2; i++) {
> +        if (sscanf(ptr, "[%"PRId64"][%"PRId64"]%c", &start, &end, &c) != 3 &&
> +            sscanf(ptr, "[%"PRId64"][]%c",          &start,       &c) != 2)
> +            return 0;
> +        ptr += strcspn(ptr, "\r\n") + 1;
> +        if (ptr >= ptr_end)
> +            return 0;
> +    }
> +    return AVPROBE_SCORE_MAX;
> +}
> +
> +static int read_ts(char **line, int64_t *pts_start, int *duration)
> +{
> +    char c;
> +    int len;
> +    int64_t end;
> +
> +    if (sscanf(*line, "[%"PRId64"][]%c%n",
> +               pts_start, &c, &len) >= 2) {
> +        *duration = -1;

> +        *line += len - 1;
> +        return 0;
> +    }
> +    if (sscanf(*line, "[%"PRId64"][%"PRId64"]%c%n",
> +               pts_start, &end, &c, &len) >= 3) {
> +        *duration = end - *pts_start;

> +        *line += len - 1;
> +        return 0;

Nit: this can be factorized (if it is worth the trouble)

> +    }
> +    return -1;
> +}
> +
> +static int mpl2_read_header(AVFormatContext *s)
> +{
> +    MPL2Context *mpl2 = s->priv_data;
> +    AVStream *st = avformat_new_stream(s, NULL);
> +    int res = 0;
> +
> +    if (!st)
> +        return AVERROR(ENOMEM);
> +    avpriv_set_pts_info(st, 64, 1, 10);
> +    st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
> +    st->codec->codec_id   = AV_CODEC_ID_MPL2;
> +
> +    while (!url_feof(s->pb)) {
> +        char line[4096];
> +        char *p = line;
> +        const int64_t pos = avio_tell(s->pb);
> +        int len = ff_get_line(s->pb, line, sizeof(line));

Nit: you could add a warning in case the line is truncated (not sure
you can really check it in an efficient way)

> +        int64_t pts_start;
> +        int duration;
> +
> +        if (!len)
> +            break;
> +
> +        line[strcspn(line, "\r\n")] = 0;
> +
> +        if (!read_ts(&p, &pts_start, &duration)) {

Nit++: read_ts(...) >= 0?

> +            AVPacket *sub;
> +
> +            sub = ff_subtitles_queue_insert(&mpl2->q, p, strlen(p), 0);
> +            if (!sub)
> +                return AVERROR(ENOMEM);
> +            sub->pos = pos;
> +            sub->pts = pts_start;
> +            sub->duration = duration;
> +        }
> +    }
> +
> +    ff_subtitles_queue_finalize(&mpl2->q);
> +    return res;
> +}
> +
> +static int mpl2_read_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> +    MPL2Context *mpl2 = s->priv_data;
> +    return ff_subtitles_queue_read_packet(&mpl2->q, pkt);
> +}
> +
> +static int mpl2_read_seek(AVFormatContext *s, int stream_index,
> +                          int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
> +{
> +    MPL2Context *mpl2 = s->priv_data;
> +    return ff_subtitles_queue_seek(&mpl2->q, s, stream_index,
> +                                   min_ts, ts, max_ts, flags);
> +}
> +
> +static int mpl2_read_close(AVFormatContext *s)
> +{
> +    MPL2Context *mpl2 = s->priv_data;
> +    ff_subtitles_queue_clean(&mpl2->q);
> +    return 0;
> +}
> +
> +AVInputFormat ff_mpl2_demuxer = {
> +    .name           = "mpl2",
> +    .long_name      = NULL_IF_CONFIG_SMALL("MPL2 subtitles"),
> +    .priv_data_size = sizeof(MPL2Context),
> +    .read_probe     = mpl2_probe,
> +    .read_header    = mpl2_read_header,
> +    .read_packet    = mpl2_read_packet,
> +    .read_seek2     = mpl2_read_seek,
> +    .read_close     = mpl2_read_close,
> +    .extensions     = "txt,mpl2",
> +};
> diff --git a/libavformat/version.h b/libavformat/version.h
> index bd14e56..8a22dd4 100644
> --- a/libavformat/version.h
> +++ b/libavformat/version.h
> @@ -30,8 +30,8 @@
>  #include "libavutil/avutil.h"
>  
>  #define LIBAVFORMAT_VERSION_MAJOR 54
> -#define LIBAVFORMAT_VERSION_MINOR 50
> -#define LIBAVFORMAT_VERSION_MICRO 102
> +#define LIBAVFORMAT_VERSION_MINOR 51
> +#define LIBAVFORMAT_VERSION_MICRO 100
>  
>  #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
>                                                 LIBAVFORMAT_VERSION_MINOR, \
> diff --git a/tests/fate/subtitles.mak b/tests/fate/subtitles.mak
> index 55c9557..9934ddf 100644
> --- a/tests/fate/subtitles.mak
> +++ b/tests/fate/subtitles.mak
> @@ -10,6 +10,9 @@ fate-sub-movtext: CMD = md5 -i $(SAMPLES)/sub/MovText_capability_tester.mp4 -f a
>  FATE_SUBTITLES-$(call ENCDEC, MOVTEXT, MOV) += fate-sub-movtextenc
>  fate-sub-movtextenc: CMD = md5 -i $(SAMPLES)/sub/MovText_capability_tester.mp4 -map 0 -scodec mov_text -f mp4 -flags +bitexact -movflags frag_keyframe+empty_moov
>  
> +FATE_SUBTITLES_ASS-$(call DEMDEC, MPL2, MPL2) += fate-sub-mpl2
> +fate-sub-mpl2: CMD = md5 -i $(SAMPLES)/sub/MPL2_capability_tester.txt -f ass
> +
>  FATE_SUBTITLES_ASS-$(call DEMDEC, REALTEXT, REALTEXT) += fate-sub-realtext
>  fate-sub-realtext: CMD = md5 -i $(SAMPLES)/sub/RealText_capability_tester.rt -f ass
>  
> diff --git a/tests/ref/fate/sub-mpl2 b/tests/ref/fate/sub-mpl2
> new file mode 100644
> index 0000000..8835dd2
> --- /dev/null
> +++ b/tests/ref/fate/sub-mpl2
> @@ -0,0 +1 @@
> +3c2fb62002aec3af16d83135a0e3b0fc

LGTM otherwise.
-- 
FFmpeg = Formidable & Frightening Mere Pitiful Encoding/decoding Gnome


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