[FFmpeg-devel] [PATCH 1/3] avformat/mux: add a format flag which ensure parsed and standardized creation time

[wm4]

On Thu, 25 Feb 2016 02:11:00 +0100
Marton Balint <cus at passwd.hu> wrote:

> This can be used for formats which write all format metadata as string to
> files, therefore non-standard creation times such as 'now' will be parsed.
> 
> The standardized creation time is UTC ISO 8601 with microsecond precision.
> 
> Signed-off-by: Marton Balint <cus at passwd.hu>
> ---
>  libavformat/avformat.h |  1 +
>  libavformat/mux.c      | 24 ++++++++++++++++++++++++
>  libavformat/version.h  |  2 +-
>  3 files changed, 26 insertions(+), 1 deletion(-)
> 
> diff --git a/libavformat/avformat.h b/libavformat/avformat.h
> index 2b6533c..ea82181 100644
> --- a/libavformat/avformat.h
> +++ b/libavformat/avformat.h
> @@ -502,6 +502,7 @@ typedef struct AVProbeData {
>                                          The user or muxer can override this through
>                                          AVFormatContext.avoid_negative_ts
>                                          */
> +#define AVFMT_NEED_PARSED_CREATION_TIME  0x80000 /**< Format needs pre-parsed standardized creation time */
>  
>  #define AVFMT_SEEK_TO_PTS   0x4000000 /**< Seeking is based on PTS */
>  
> diff --git a/libavformat/mux.c b/libavformat/mux.c
> index 789c811..9a39064 100644
> --- a/libavformat/mux.c
> +++ b/libavformat/mux.c
> @@ -36,10 +36,12 @@
>  #include "libavutil/mathematics.h"
>  #include "libavutil/parseutils.h"
>  #include "libavutil/time.h"
> +#include "libavutil/time_internal.h"
>  #include "riff.h"
>  #include "audiointerleave.h"
>  #include "url.h"
>  #include <stdarg.h>
> +#include <time.h>
>  #if CONFIG_NETWORK
>  #include "network.h"
>  #endif
> @@ -383,6 +385,28 @@ FF_ENABLE_DEPRECATION_WARNINGS
>          }
>      }
>  
> +    /* pre-parse creation time for formats that need it */
> +    if (s->oformat->flags & AVFMT_NEED_PARSED_CREATION_TIME) {
> +        int64_t timestamp;
> +        if (ff_parse_creation_time_metadata(s, &timestamp, 0) == 1) {
> +            time_t seconds = timestamp / 1000000;
> +            struct tm *ptm, tmbuf;
> +            ptm = gmtime_r(&seconds, &tmbuf);
> +            if (ptm) {
> +                char buf[32];
> +                if (!strftime(buf, sizeof(buf), "%Y-%m-%dT%H:%M:%S", ptm)) {
> +                    ret = AVERROR_EXTERNAL;
> +                    goto fail;
> +                }
> +                av_strlcatf(buf, sizeof(buf), ".%06dZ", (int)(timestamp % 1000000));
> +                av_dict_set(&s->metadata, "creation_time", buf, 0);
> +            } else {
> +                ret = AVERROR_EXTERNAL;
> +                goto fail;
> +            }
> +        }
> +    }
> +
>      /* set muxer identification string */
>      if (!(s->flags & AVFMT_FLAG_BITEXACT)) {
>          av_dict_set(&s->metadata, "encoder", LIBAVFORMAT_IDENT, 0);
> diff --git a/libavformat/version.h b/libavformat/version.h
> index 82a8892..9f4ede7 100644
> --- a/libavformat/version.h
> +++ b/libavformat/version.h
> @@ -31,7 +31,7 @@
>  
>  #define LIBAVFORMAT_VERSION_MAJOR  57
>  #define LIBAVFORMAT_VERSION_MINOR  26
> -#define LIBAVFORMAT_VERSION_MICRO 100
> +#define LIBAVFORMAT_VERSION_MICRO 101
>  
>  #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
>                                                 LIBAVFORMAT_VERSION_MINOR, \

Wouldn't it be better to make this a function, and adding a function
call to the muxers which need this, instead of adding yet another flag
and adding that flag to the muxers?