[FFmpeg-devel] [PATCH 04/11] lavf/microdvd: rewrite using subtitles queue API.

Nicolas George nicolas.george at normalesup.org
Sat Jun 23 13:07:43 CEST 2012


Le quintidi 5 messidor, an CCXX, Clément Bœsch a écrit :
> ---
>  libavformat/microdvddec.c | 147 ++++++++++++++++++----------------------------
>  1 file changed, 58 insertions(+), 89 deletions(-)
> 
> diff --git a/libavformat/microdvddec.c b/libavformat/microdvddec.c
> index b1229fa..113d62f 100644
> --- a/libavformat/microdvddec.c
> +++ b/libavformat/microdvddec.c
> @@ -1,6 +1,7 @@
>  /*
>   * MicroDVD subtitle demuxer
>   * Copyright (c) 2010  Aurelien Jacobs <aurel at gnuage.org>
> + * Copyright (c) 2012  Clément Bœsch <ubitux at gmail.com>
>   *
>   * This file is part of FFmpeg.
>   *
> @@ -21,16 +22,14 @@
>  
>  #include "avformat.h"
>  #include "internal.h"
> +#include "subtitles.h"
>  #include "libavutil/intreadwrite.h"
>  
>  #define MAX_LINESIZE 2048
>  
>  
>  typedef struct {
> -    uint8_t lines[3][MAX_LINESIZE];
> -    int64_t pos[3];
> -    AVPacket last_pkt;
> -    int last_pkt_ready;
> +    FFDemuxSubtitlesQueue q;
>  } MicroDVDContext;
>  
>  
> @@ -52,36 +51,6 @@ static int microdvd_probe(AVProbeData *p)
>      return AVPROBE_SCORE_MAX;
>  }
>  
> -static int microdvd_read_header(AVFormatContext *s)
> -{
> -    AVRational pts_info = (AVRational){ 2997, 125 };  /* default: 23.976 fps */
> -    MicroDVDContext *microdvd = s->priv_data;
> -    AVStream *st = avformat_new_stream(s, NULL);
> -    int i, frame;
> -    double fps;
> -    char c;
> -
> -    if (!st)
> -        return AVERROR(ENOMEM);
> -    for (i=0; i<FF_ARRAY_ELEMS(microdvd->lines); i++) {
> -        microdvd->pos[i] = avio_tell(s->pb);
> -        ff_get_line(s->pb, microdvd->lines[i], sizeof(microdvd->lines[i]));
> -        if ((sscanf(microdvd->lines[i], "{%d}{}%6lf",    &frame, &fps) == 2 ||
> -             sscanf(microdvd->lines[i], "{%d}{%*d}%6lf", &frame, &fps) == 2)
> -            && frame <= 1 && fps > 3 && fps < 100)
> -            pts_info = av_d2q(fps, 100000);
> -        if (sscanf(microdvd->lines[i], "{DEFAULT}{}%c", &c) == 1) {
> -            st->codec->extradata = av_strdup(microdvd->lines[i] + 11);
> -            st->codec->extradata_size = strlen(st->codec->extradata);
> -            i--;
> -        }
> -    }
> -    avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num);
> -    st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
> -    st->codec->codec_id   = CODEC_ID_MICRODVD;
> -    return 0;
> -}
> -
>  static int64_t get_pts(const char *buf)
>  {
>      int frame;
> @@ -101,68 +70,67 @@ static int get_duration(const char *buf)
>      return -1;
>  }
>  
> -static int microdvd_read_packet(AVFormatContext *s, AVPacket *pkt)
> +static int microdvd_read_header(AVFormatContext *s)
>  {
> +    AVRational pts_info = (AVRational){ 2997, 125 };  /* default: 23.976 fps */
>      MicroDVDContext *microdvd = s->priv_data;
> -    char buffer[MAX_LINESIZE];
> -    int64_t pos = avio_tell(s->pb);
> -    int i, len = 0, res = AVERROR_EOF;
> -
> -    // last packet has its duration set but couldn't be raised earlier
> -    if (microdvd->last_pkt_ready) {
> -        *pkt = microdvd->last_pkt;
> -        microdvd->last_pkt_ready = 0;
> -        return 0;
> -    }
> +    AVStream *st = avformat_new_stream(s, NULL);
> +    int i = 0;
> +    char line[MAX_LINESIZE];
> +
> +    if (!st)
> +        return AVERROR(ENOMEM);
> +
> +    while (!url_feof(s->pb)) {
> +        AVPacket *sub;
> +        int64_t pos = avio_tell(s->pb);
> +        int len = ff_get_line(s->pb, line, sizeof(line));
>  
> -    for (i=0; i<FF_ARRAY_ELEMS(microdvd->lines); i++) {
> -        if (microdvd->lines[i][0]) {
> -            strcpy(buffer, microdvd->lines[i]);
> -            pos = microdvd->pos[i];
> -            len = strlen(buffer);
> -            microdvd->lines[i][0] = 0;
> +        if (!len)
>              break;
> -        }
> -    }
> -    if (!len)
> -        len = ff_get_line(s->pb, buffer, sizeof(buffer));
> -
> -    if (microdvd->last_pkt.duration == -1 && !buffer[0]) {
> -        // if the previous subtitle line had no duration, last until the end of
> -        // the presentation
> -        microdvd->last_pkt.duration = 0;
> -        *pkt = microdvd->last_pkt;
> -        pkt->duration = -1;
> -        res = 0;
> -    } else if (buffer[0] && !(res = av_new_packet(pkt, len))) {
> -        memcpy(pkt->data, buffer, len);
> -        pkt->flags |= AV_PKT_FLAG_KEY;
> -        pkt->pos = pos;
> -        pkt->pts = pkt->dts = get_pts(buffer);
> -
> -        if (pkt->pts != AV_NOPTS_VALUE) {
> -            pkt->duration = get_duration(buffer);
> -            if (microdvd->last_pkt.duration == -1) {
> -                // previous packet wasn't raised because it was lacking the
> -                // duration info, so set its duration with the new packet pts
> -                // and raise it
> -                AVPacket tmp_pkt;
> -
> -                tmp_pkt = microdvd->last_pkt;
> -                tmp_pkt.duration = pkt->pts - tmp_pkt.pts;
> -                microdvd->last_pkt = *pkt;
> -                microdvd->last_pkt_ready = pkt->duration != -1;
> -                *pkt = tmp_pkt;
> -            } else if (pkt->duration == -1) {
> -                // no packet without duration queued, and current one is
> -                // lacking the duration info, we need to parse another subtitle
> -                // event.
> -                microdvd->last_pkt = *pkt;
> -                res = AVERROR(EAGAIN);
> +        if (i < 3) {
> +            int frame;
> +            double fps;
> +            char c;
> +
> +            i++;
> +            if ((sscanf(line, "{%d}{}%6lf",    &frame, &fps) == 2 ||
> +                 sscanf(line, "{%d}{%*d}%6lf", &frame, &fps) == 2)
> +                && frame <= 1 && fps > 3 && fps < 100)
> +                pts_info = av_d2q(fps, 100000);
> +            if (!st->codec->extradata && sscanf(line, "{DEFAULT}{}%c", &c) == 1) {
> +                st->codec->extradata = av_strdup(line + 11);
> +                if (!st->codec->extradata)
> +                    return AVERROR(ENOMEM);
> +                st->codec->extradata_size = strlen(st->codec->extradata) + 1;
> +                continue;
>              }
>          }
> +        sub = ff_subtitles_queue_insert(&microdvd->q, line, len, 0);
> +        if (!sub)
> +            return AVERROR(ENOMEM);
> +        sub->pos = pos;
> +        sub->pts = get_pts(sub->data);
> +        sub->duration = get_duration(sub->data);

There is a discussion about the correct field to store the duration of the
subtitles (with the risk that the 32-bits duration field may be too small).

The same applies probably to other patches in this series.

>      }
> -    return res;
> +    ff_subtitles_queue_finalize(&microdvd->q);
> +    avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num);
> +    st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
> +    st->codec->codec_id   = CODEC_ID_MICRODVD;
> +    return 0;
> +}
> +
> +static int microdvd_read_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> +    MicroDVDContext *microdvd = s->priv_data;
> +    return ff_subtitles_queue_read_packet(&microdvd->q, pkt);
> +}
> +
> +static int microdvd_read_close(AVFormatContext *s)
> +{
> +    MicroDVDContext *microdvd = s->priv_data;
> +    ff_subtitles_queue_free(&microdvd->q);
> +    return 0;
>  }
>  
>  AVInputFormat ff_microdvd_demuxer = {
> @@ -172,5 +140,6 @@ AVInputFormat ff_microdvd_demuxer = {
>      .read_probe     = microdvd_probe,
>      .read_header    = microdvd_read_header,
>      .read_packet    = microdvd_read_packet,
> +    .read_close     = microdvd_read_close,
>      .flags          = AVFMT_GENERIC_INDEX,
>  };

No other remarks from me.

Regards,

-- 
  Nicolas George
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