[FFmpeg-devel] [PATCH] lavf/segment: add support to segment list sliding window listing

[Steven Liu]

2012/12/21 Stefano Sabatini <stefasab at gmail.com>:
> In particular, should fix trac ticket #1842.
> ---
>  libavformat/segment.c |   65 +++++++++++++++++++++++++++++++++++++------------
>  1 file changed, 50 insertions(+), 15 deletions(-)
>
> diff --git a/libavformat/segment.c b/libavformat/segment.c
> index 4ad69a4..b4752a5 100644
> --- a/libavformat/segment.c
> +++ b/libavformat/segment.c
> @@ -92,6 +92,9 @@ typedef struct {
>      int has_video;
>
>      SegmentListEntry cur_entry;
> +    SegmentListEntry *segment_list_entries;
> +    SegmentListEntry *segment_list_entries_end;
> +
>      int is_first_pkt;      ///< tells if it is the first packet in the segment
>  } SegmentContext;
>
> @@ -208,15 +211,19 @@ static int segment_list_open(AVFormatContext *s)
>          return ret;
>      seg->list_max_segment_time = 0;
>
> -    if (seg->list_type == LIST_TYPE_M3U8) {
> +    if (seg->list_type == LIST_TYPE_M3U8 && seg->segment_list_entries) {
> +        SegmentListEntry *entry;
> +        double max_duration = 0;
> +
>          avio_printf(seg->list_pb, "#EXTM3U\n");
>          avio_printf(seg->list_pb, "#EXT-X-VERSION:3\n");
> -        avio_printf(seg->list_pb, "#EXT-X-MEDIA-SEQUENCE:%d\n", seg->segment_idx);
> +        avio_printf(seg->list_pb, "#EXT-X-MEDIA-SEQUENCE:%d\n", seg->segment_list_entries->index);
>          avio_printf(seg->list_pb, "#EXT-X-ALLOWCACHE:%d\n",
>                      !!(seg->list_flags & SEGMENT_LIST_FLAG_CACHE));
> -        if (seg->list_flags & SEGMENT_LIST_FLAG_LIVE)
> -            avio_printf(seg->list_pb,
> -                        "#EXT-X-TARGETDURATION:%"PRId64"\n", seg->time / 1000000);
> +
> +        for (entry = seg->segment_list_entries; entry; entry = entry->next)
> +            max_duration = FFMAX(max_duration, entry->end_time - entry->start_time);
> +        avio_printf(seg->list_pb, "#EXT-X-TARGETDURATION:%"PRId64"\n", (int64_t)ceil(max_duration));
>      }
>
>      return ret;
> @@ -226,12 +233,8 @@ static void segment_list_close(AVFormatContext *s)
>  {
>      SegmentContext *seg = s->priv_data;
>
> -    if (seg->list_type == LIST_TYPE_M3U8) {
> -        if (!(seg->list_flags & SEGMENT_LIST_FLAG_LIVE))
> -            avio_printf(seg->list_pb, "#EXT-X-TARGETDURATION:%d\n",
> -                        (int)ceil(seg->list_max_segment_time));
> +    if (seg->list_type == LIST_TYPE_M3U8)
>          avio_printf(seg->list_pb, "#EXT-X-ENDLIST\n");
> -    }
>
>      avio_close(seg->list_pb);
>  }
> @@ -273,15 +276,38 @@ static int segment_end(AVFormatContext *s, int write_trailer)
>                 oc->filename);
>
>      if (seg->list) {
> -        if (seg->list_size && !(seg->segment_count % seg->list_size)) {
> +        if (seg->list_size || seg->list_type == LIST_TYPE_M3U8) {
> +            SegmentListEntry *entry = av_mallocz(sizeof(*entry));
> +            if (!entry) {
> +                ret = AVERROR(ENOMEM);
> +                goto end;
> +            }
> +
> +            /* append new element */
> +            memcpy(entry, &seg->cur_entry, sizeof(*entry));
> +            if (!seg->segment_list_entries)
> +                seg->segment_list_entries = seg->segment_list_entries_end = entry;
> +            else
> +                seg->segment_list_entries_end->next = entry;
> +            seg->segment_list_entries_end = entry;
> +
> +            /* drop first item */
> +            if (seg->list_size && seg->segment_count > seg->list_size) {
> +                entry = seg->segment_list_entries;
> +                seg->segment_list_entries = seg->segment_list_entries->next;
> +                av_freep(&entry);
> +            }
> +
>              segment_list_close(s);
>              if ((ret = segment_list_open(s)) < 0)
>                  goto end;
> +            for (entry = seg->segment_list_entries; entry; entry = entry->next)
> +                segment_list_print_entry(seg->list_pb, seg->list_type, entry);
> +        } else {
> +            segment_list_print_entry(seg->list_pb, seg->list_type, &seg->cur_entry);
> +            seg->list_max_segment_time =
> +                FFMAX(seg->cur_entry.end_time - seg->cur_entry.start_time, seg->list_max_segment_time);
>          }
> -
> -        segment_list_print_entry(seg->list_pb, seg->list_type, &seg->cur_entry);
> -        seg->list_max_segment_time =
> -            FFMAX(seg->cur_entry.end_time - seg->cur_entry.start_time, seg->list_max_segment_time);
>          avio_flush(seg->list_pb);
>      }
>
> @@ -644,6 +670,8 @@ static int seg_write_trailer(struct AVFormatContext *s)
>  {
>      SegmentContext *seg = s->priv_data;
>      AVFormatContext *oc = seg->avf;
> +    SegmentListEntry *cur, *next;
> +
>      int ret;
>      if (!seg->write_header_trailer) {
>          if ((ret = segment_end(s, 0)) < 0)
> @@ -662,6 +690,13 @@ fail:
>      av_freep(&seg->times);
>      av_freep(&seg->frames);
>
> +    cur = seg->segment_list_entries;
> +    while (cur) {
> +        next = cur->next;
> +        av_free(cur);
> +        cur = next;
> +    }
> +
>      avformat_free_context(oc);
>      return ret;
>  }
> --
> 1.7.9.5
>

Hi Stefano,

         The version always 3?  I saw the m3u8 spec have upgrade to 5.
         Can this patch upgrade it? Or version 3 is use by more engine?