On date Friday 2016-01-29 12:18:02 +0100, Martin Vignali encoded:
> Ping
>
> ---------- Forwarded message ----------
> From: Martin Vignali <martin.vign...@gmail.com>
> Date: 2015-10-03 15:49 GMT+02:00
> Subject: libavformat/segment : add option to increment timecode
> To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
>
>
> Hello,
>
> in attach a patch, who add an option to increment timecode using segment.
>
> To test :
>
> ffmpeg -i src.mov -timecode 10:00:00:00 -vcodec copy -f segment
> -segment_time 2 -reset_timestamps 1 -increment_tc 1 target_%03d.mov
>
> the second file have timecode 10:00:02:00 (after the patch)
> instead of 10:00:00:00 (before the patch)
>
>
> This patch is useful for two kind of uses :
> - splitting a file, but keeping timecode of each part
> - have a continuous timecode when recording a stream using segment.
>
>
> Comments welcome.
>
> Martin
> From e53698b08211a818e1fe924a532e142bbb64fc87 Mon Sep 17 00:00:00 2001
> From: Martin Vignali <martin.vign...@gmail.com>
> Date: Sat, 3 Oct 2015 15:39:41 +0200
> Subject: [PATCH] add increment timecode option using segment.
>
> ---
> libavformat/segment.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
Please add docs in doc/muxers.texi.
> diff --git a/libavformat/segment.c b/libavformat/segment.c
> index 36417f2..f3e1ab3 100644
> --- a/libavformat/segment.c
> +++ b/libavformat/segment.c
> @@ -40,6 +40,7 @@
> #include "libavutil/parseutils.h"
> #include "libavutil/mathematics.h"
> #include "libavutil/time.h"
> +#include "libavutil/timecode.h"
> #include "libavutil/time_internal.h"
> #include "libavutil/timestamp.h"
>
> @@ -92,6 +93,7 @@ typedef struct SegmentContext {
> char *time_str; ///< segment duration specification string
> int64_t time; ///< segment duration
> int use_strftime; ///< flag to expand filename with strftime
> + int increment_tc; ///< flag for increment timecode if found
nit: flag to increment ...
>
> char *times_str; ///< segment times specification string
> int64_t *times; ///< list of segment interval specification
> @@ -221,6 +223,30 @@ static int segment_start(AVFormatContext *s, int
> write_header)
> SegmentContext *seg = s->priv_data;
> AVFormatContext *oc = seg->avf;
> int err = 0;
> + AVTimecode tc;
> + AVRational rate;
> +
> + if (seg->increment_tc){
style nit: if (...)_{
here and below
> + AVDictionaryEntry * tcr = av_dict_get(s->metadata, "timecode", NULL,
> 0);
> + if (tcr){
> + if (s->nb_streams > 0){
> + rate = s->streams[0]->avg_frame_rate;//Get fps from first
> stream
this looks a bit arbitrary, why the first stream?
> + err = av_timecode_init_from_string(&tc, rate, tcr->value, s);
> + if (err < 0)
> + return err;
> + tc.start += (int)(seg->time / 1000000.) *
> av_q2d(rate);//second count * fps
You're losing precision here. Consider using the rescaling utilities
in libavutil/mathematics.h or something like (seg->time * rate.num) /
(rate.den * 1000000).
[...]
--
FFmpeg = Frightening & Faithful Mythic Programmable Elastic Gadget
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