[FFmpeg-devel] [PATCH 2/7] lavf/segment: add option to segment by chapter
Steven Liu
lingjiujianke at gmail.com
Tue Aug 1 09:54:29 EEST 2017
2017-08-01 14:33 GMT+08:00 Rodger Combs <rodger.combs at gmail.com>:
> ---
> doc/muxers.texi | 6 +++++
> libavformat/segment.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++----
> libavformat/version.h | 2 +-
> 3 files changed, 67 insertions(+), 6 deletions(-)
>
> diff --git a/doc/muxers.texi b/doc/muxers.texi
> index 94472ce..23ef2e7 100644
> --- a/doc/muxers.texi
> +++ b/doc/muxers.texi
> @@ -1538,6 +1538,12 @@ This option specifies to start a new segment whenever a reference
> stream key frame is found and the sequential number (starting from 0)
> of the frame is greater or equal to the next value in the list.
>
> + at item segment_chapters @var{1|0}
> +Split each chapter into its own segment. Metadata from the chapters
> +will be written to the corresponding segments. If this option is selected
> +and the filename contains tokens in the format @code{$varname$}, they
> +will be replaced by the corresponding metadata values.
> +
> @item segment_wrap @var{limit}
> Wrap around segment index once it reaches @var{limit}.
>
> diff --git a/libavformat/segment.c b/libavformat/segment.c
> index 0e8bcdd..590f62b 100644
> --- a/libavformat/segment.c
> +++ b/libavformat/segment.c
> @@ -106,6 +106,8 @@ typedef struct SegmentContext {
> int frame_count; ///< total number of reference frames
> int segment_frame_count; ///< number of reference frames in the segment
>
> + int split_chapters; ///< split on chapter markers
> +
> int64_t time_delta;
> int individual_header_trailer; /**< Set by a private option. */
> int write_header_trailer; /**< Set by a private option. */
> @@ -186,6 +188,43 @@ static int segment_mux_init(AVFormatContext *s)
> return 0;
> }
>
> +static int replace_variables(AVFormatContext *oc)
> +{
> + char name[sizeof(oc->filename)];
> + char *p = name;
> + char *out = oc->filename;
> + strncpy(name, oc->filename, sizeof(name));
> + while (*p) {
> + char c = *p++;
> + if (c == '$') {
> + if (*p == '$') {
> + p++;
> + goto append;
> + } else {
> + int len;
> + const char *val;
> + const AVDictionaryEntry *e;
> + int end = strcspn(p, "$");
> + if (p[end] == '\0')
> + continue;
> + 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);
why not av_strlcpy?
> + out = FFMIN(oc->filename + sizeof(oc->filename) - 1, out + len);
> + p += end + 1;
> + }
> + } else {
> +append:
> + if (out - oc->filename < sizeof(oc->filename) - 1)
> + *out++ = c;
> + }
> + }
> + *out = '\0';
> + return 0;
> +}
> +
> static int set_segment_filename(AVFormatContext *s)
> {
> SegmentContext *seg = s->priv_data;
> @@ -210,6 +249,9 @@ static int set_segment_filename(AVFormatContext *s)
> return AVERROR(EINVAL);
> }
>
> + if (seg->split_chapters)
> + replace_variables(oc);
> +
> /* copy modified name in list entry */
> size = strlen(av_basename(oc->filename)) + 1;
> if (seg->entry_prefix)
> @@ -236,6 +278,8 @@ static int segment_start(AVFormatContext *s, int write_header)
> if ((err = segment_mux_init(s)) < 0)
> return err;
> oc = seg->avf;
> + if (seg->split_chapters && seg->segment_count < s->nb_chapters && (err = av_dict_copy(&oc->metadata, s->chapters[seg->segment_count]->metadata, 0)) < 0)
> + return err;
> }
>
> seg->segment_idx++;
> @@ -659,10 +703,14 @@ static int seg_init(AVFormatContext *s)
> "you can use output_ts_offset instead of it\n");
> }
>
> - if (!!seg->time_str + !!seg->times_str + !!seg->frames_str > 1) {
> + if (seg->segment_idx < 0)
> + seg->segment_idx = seg->split_chapters;
> +
> + if (!!seg->time_str + !!seg->times_str + !!seg->frames_str + !!seg->split_chapters > 1) {
> av_log(s, AV_LOG_ERROR,
> - "segment_time, segment_times, and segment_frames options "
> - "are mutually exclusive, select just one of them\n");
> + "segment_time, segment_times, segment_frames, and "
> + "segment_chapters options are mutually exclusive; "
> + "select just one of them\n");
> return AVERROR(EINVAL);
> }
>
> @@ -672,7 +720,7 @@ static int seg_init(AVFormatContext *s)
> } else if (seg->frames_str) {
> if ((ret = parse_frames(s, &seg->frames, &seg->nb_frames, seg->frames_str)) < 0)
> return ret;
> - } else {
> + } else if (!seg->split_chapters) {
> /* set default value if not specified */
> if (!seg->time_str)
> seg->time_str = av_strdup("2");
> @@ -739,6 +787,9 @@ static int seg_init(AVFormatContext *s)
> if ((ret = segment_mux_init(s)) < 0)
> return ret;
>
> + if (seg->split_chapters && s->nb_chapters && (ret = av_dict_copy(&seg->avf->metadata, s->chapters[0]->metadata, 0)) < 0)
> + return ret;
> +
> if ((ret = set_segment_filename(s)) < 0)
> return ret;
> oc = seg->avf;
> @@ -860,6 +911,9 @@ calc_times:
> } else if (seg->frames) {
> start_frame = seg->segment_count < seg->nb_frames ?
> seg->frames[seg->segment_count] : INT_MAX;
> + } else if (seg->split_chapters) {
> + end_pts = seg->segment_count + 1 < s->nb_chapters ?
> + av_rescale_q(s->chapters[seg->segment_count]->end, s->chapters[seg->segment_count]->time_base, AV_TIME_BASE_Q) : INT64_MAX;
> } else {
> if (seg->use_clocktime) {
> int64_t avgt = av_gettime();
> @@ -1042,9 +1096,10 @@ static const AVOption options[] = {
> { "segment_time_delta","set approximation value used for the segment times", OFFSET(time_delta), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, 0, E },
> { "segment_times", "set segment split time points", OFFSET(times_str),AV_OPT_TYPE_STRING,{.str = NULL}, 0, 0, E },
> { "segment_frames", "set segment split frame numbers", OFFSET(frames_str),AV_OPT_TYPE_STRING,{.str = NULL}, 0, 0, E },
> + { "segment_chapters", "split segments on chapter markers", OFFSET(split_chapters), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E },
> { "segment_wrap", "set number after which the index wraps", OFFSET(segment_idx_wrap), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E },
> { "segment_list_entry_prefix", "set base url prefix for segments", OFFSET(entry_prefix), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
> - { "segment_start_number", "set the sequence number of the first segment", OFFSET(segment_idx), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E },
> + { "segment_start_number", "set the sequence number of the first segment", OFFSET(segment_idx), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, E },
> { "segment_wrap_number", "set the number of wrap before the first segment", OFFSET(segment_idx_wrap_nb), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E },
> { "strftime", "set filename expansion with strftime at segment creation", OFFSET(use_strftime), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, E },
> { "increment_tc", "increment timecode between each segment", OFFSET(increment_tc), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, E },
> diff --git a/libavformat/version.h b/libavformat/version.h
> index a8cf4c1..4d12f5b 100644
> --- a/libavformat/version.h
> +++ b/libavformat/version.h
> @@ -33,7 +33,7 @@
> // Also please add any ticket numbers that you believe might be affected here
> #define LIBAVFORMAT_VERSION_MAJOR 57
> #define LIBAVFORMAT_VERSION_MINOR 77
> -#define LIBAVFORMAT_VERSION_MICRO 100
> +#define LIBAVFORMAT_VERSION_MICRO 101
>
> #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
> LIBAVFORMAT_VERSION_MINOR, \
> --
> 2.6.4
>
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