[FFmpeg-devel] [PATCH 4/7] lavf/segment: write attached pictures to all segments by default

Rostislav Pehlivanov atomnuker at gmail.com
Wed Nov 22 02:56:49 EET 2017


On 2 August 2017 at 07:30, Rodger Combs <rodger.combs at gmail.com> wrote:

> ---
>  doc/muxers.texi       |  4 ++++
>  libavformat/segment.c | 40 +++++++++++++++++++++++++++++-----------
>  2 files changed, 33 insertions(+), 11 deletions(-)
>
> diff --git a/doc/muxers.texi b/doc/muxers.texi
> index 23ef2e7..93147e1 100644
> --- a/doc/muxers.texi
> +++ b/doc/muxers.texi
> @@ -1576,6 +1576,10 @@ argument must be a time duration specification, and
> defaults to 0.
>  If enabled, write an empty segment if there are no packets during the
> period a
>  segment would usually span. Otherwise, the segment will be filled with
> the next
>  packet written. Defaults to @code{0}.
> +
> + at item dup_attached_pics @var{1|0}
> +If enabled, attached-picture packets will be written to all segments,
> rather
> +than only the first. Defaults to @code{1}.
>  @end table
>
>  @subsection Examples
> diff --git a/libavformat/segment.c b/libavformat/segment.c
> index ef0a915..632476e 100644
> --- a/libavformat/segment.c
> +++ b/libavformat/segment.c
> @@ -119,6 +119,7 @@ typedef struct SegmentContext {
>      int   reference_stream_index;
>      int   break_non_keyframes;
>      int   write_empty;
> +    int   dup_attached_pics;
>
>      int use_rename;
>      char temp_list_filename[1024];
> @@ -126,6 +127,8 @@ typedef struct SegmentContext {
>      SegmentListEntry cur_entry;
>      SegmentListEntry *segment_list_entries;
>      SegmentListEntry *segment_list_entries_end;
> +
> +    AVPacket *attached_pics;
>  } SegmentContext;
>
>  static void print_csv_escaped_str(AVIOContext *ctx, const char *str)
> @@ -193,16 +196,15 @@ static int replace_variables(AVFormatContext *oc)
>  {
>      char name[sizeof(oc->filename)];
>      char *p = name;
> -    char *out = oc->filename;
> +    AVBPrint bprint;
>      strncpy(name, oc->filename, sizeof(name));
> +    av_bprint_init_for_buffer(&bprint, oc->filename,
> sizeof(oc->filename));
>      while (*p) {
>          char c = *p++;
>          if (c == '$') {
>              if (*p == '$') {
> -                p++;
> -                goto append;
> +                av_bprint_chars(&bprint, c, 1);
>              } else {
> -                int len;
>                  const char *val;
>                  const AVDictionaryEntry *e;
>                  int end = strcspn(p, "$");
> @@ -211,18 +213,13 @@ static int replace_variables(AVFormatContext *oc)
>                  p[end] = '\0';
>                  e = av_dict_get(oc->metadata, p, NULL, 0);
>                  val = e ? e->value : "(unknown)";
> -                len = strlen(val);
> -                strncpy(out, val, oc->filename + sizeof(oc->filename) - 1
> - out);
> -                out = FFMIN(oc->filename + sizeof(oc->filename) - 1, out
> + len);
> +                av_bprint_append_data(&bprint, val, strlen(val));
>                  p += end + 1;
>              }
>          } else {
> -append:
> -            if (out - oc->filename < sizeof(oc->filename) - 1)
> -                *out++ = c;
> +            av_bprint_chars(&bprint, c, 1);
>          }
>      }
> -    *out = '\0';
>      return 0;
>  }
>
> @@ -301,6 +298,7 @@ static int segment_start(AVFormatContext *s, int
> write_header)
>          av_opt_set(oc->priv_data, "mpegts_flags", "+resend_headers", 0);
>
>      if (write_header) {
> +        int i;
>          AVDictionary *options = NULL;
>          av_dict_copy(&options, seg->format_options, 0);
>          av_dict_set(&options, "fflags", "-autobsf", 0);
> @@ -308,6 +306,13 @@ static int segment_start(AVFormatContext *s, int
> write_header)
>          av_dict_free(&options);
>          if (err < 0)
>              return err;
> +        for (i = 0; i < s->nb_streams; i++) {
> +            if (seg->dup_attached_pics &&
> +                s->streams[i]->disposition & AV_DISPOSITION_ATTACHED_PIC
> &&
> +                seg->attached_pics[i].data) {
> +                av_write_frame(oc, &seg->attached_pics[i]);
> +            }
> +        }
>      }
>
>      seg->segment_frame_count = 0;
> @@ -680,6 +685,12 @@ static void seg_free(AVFormatContext *s)
>      ff_format_io_close(seg->avf, &seg->list_pb);
>      avformat_free_context(seg->avf);
>      seg->avf = NULL;
> +    if (seg->attached_pics) {
> +        int i;
> +        for (i = 0; i < s->nb_streams; i++)
> +            av_packet_unref(&seg->attached_pics[i]);
> +        av_freep(&seg->attached_pics);
> +    }
>  }
>
>  static int seg_init(AVFormatContext *s)
> @@ -840,6 +851,9 @@ static int seg_init(AVFormatContext *s)
>          avpriv_set_pts_info(outer_st, inner_st->pts_wrap_bits,
> inner_st->time_base.num, inner_st->time_base.den);
>      }
>
> +    if (seg->dup_attached_pics && !(seg->attached_pics =
> av_calloc(s->nb_streams, sizeof(AVPacket))))
> +        return AVERROR(ENOMEM);
> +
>      if (oc->avoid_negative_ts > 0 && s->avoid_negative_ts < 0)
>          s->avoid_negative_ts = 1;
>
> @@ -905,6 +919,9 @@ static int seg_write_packet(AVFormatContext *s,
> AVPacket *pkt)
>      if (!seg->avf || !seg->avf->pb)
>          return AVERROR(EINVAL);
>
> +    if (seg->dup_attached_pics && st->disposition &
> AV_DISPOSITION_ATTACHED_PIC)
> +        av_copy_packet(&seg->attached_pics[pkt->stream_index], pkt);
>

Makes sense, if the packet is refcounted this sets fields and does a ref
rather than a memcpy.



> +
>  calc_times:
>      if (seg->times) {
>          end_pts = seg->segment_count < seg->nb_times ?
> @@ -1111,6 +1128,7 @@ static const AVOption options[] = {
>      { "reset_timestamps", "reset timestamps at the begin of each
> segment", OFFSET(reset_timestamps), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E },
>      { "initial_offset", "set initial timestamp offset",
> OFFSET(initial_offset), AV_OPT_TYPE_DURATION, {.i64 = 0}, -INT64_MAX,
> INT64_MAX, E },
>      { "write_empty_segments", "allow writing empty 'filler' segments",
> OFFSET(write_empty), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E },
> +    { "dup_attached_pics",  "write attached pictures to all segments",
> OFFSET(dup_attached_pics), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, E },
>      { NULL },
>  };
>
> --
> 2.6.4
>
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> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>

LGTM


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