[FFmpeg-devel] [PATCH 3/3] avformat: fix decoded creation_time timestamps

[Marton Balint]

On Fri, 1 Jul 2016, Marton Balint wrote:

> Use proper ISO 8601 timestamps which also signal that they are in UTC.
>
> This changes the format of creation_time and modification_date metadata values
> from 2016-06-01 22:30:00 to 2016-01-01T22:30:00.000000Z
>
> Fixes ticket #5673.
>

I'd like to apply this soon as well. Changing the format of creation_time 
and modification_time in the metadata might be considered a hostile 
move against library users, so I would not mind some comments that it is 
OK. Maybe an entry in API changes is enough?

Thanks,
Marton

> Signed-off-by: Marton Balint <cus at passwd.hu>
> ---
> libavformat/matroskadec.c |  7 +------
> libavformat/mov.c         |  9 +--------
> libavformat/mxfdec.c      | 14 ++++----------
> libavformat/version.h     |  2 +-
> 4 files changed, 7 insertions(+), 25 deletions(-)
>
> diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
> index f3d701f..82ff2ba 100644
> --- a/libavformat/matroskadec.c
> +++ b/libavformat/matroskadec.c
> @@ -1691,13 +1691,8 @@ static int matroska_aac_sri(int samplerate)
> 
> static void matroska_metadata_creation_time(AVDictionary **metadata, int64_t date_utc)
> {
> -    char buffer[32];
>     /* Convert to seconds and adjust by number of seconds between 2001-01-01 and Epoch */
> -    time_t creation_time = date_utc / 1000000000 + 978307200;
> -    struct tm tmpbuf, *ptm = gmtime_r(&creation_time, &tmpbuf);
> -    if (!ptm) return;
> -    if (strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", ptm))
> -        av_dict_set(metadata, "creation_time", buffer, 0);
> +    avpriv_dict_set_timestamp(metadata, "creation_time", date_utc / 1000 + 978307200000000LL);
> }
> 
> static int matroska_parse_flac(AVFormatContext *s,
> diff --git a/libavformat/mov.c b/libavformat/mov.c
> index 485bb0b..cb9490c 100644
> --- a/libavformat/mov.c
> +++ b/libavformat/mov.c
> @@ -1155,17 +1155,10 @@ static int mov_read_moof(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> 
> static void mov_metadata_creation_time(AVDictionary **metadata, int64_t time)
> {
> -    char buffer[32];
>     if (time) {
> -        struct tm *ptm, tmbuf;
> -        time_t timet;
>         if(time >= 2082844800)
>             time -= 2082844800;  /* seconds between 1904-01-01 and Epoch */
> -        timet = time;
> -        ptm = gmtime_r(&timet, &tmbuf);
> -        if (!ptm) return;
> -        if (strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", ptm))
> -            av_dict_set(metadata, "creation_time", buffer, 0);
> +        avpriv_dict_set_timestamp(metadata, "creation_time", time * 1000000);
>     }
> }
> 
> diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
> index 0affca9..0b16463 100644
> --- a/libavformat/mxfdec.c
> +++ b/libavformat/mxfdec.c
> @@ -50,6 +50,7 @@
> #include "libavutil/mathematics.h"
> #include "libavcodec/bytestream.h"
> #include "libavutil/intreadwrite.h"
> +#include "libavutil/parseutils.h"
> #include "libavutil/timecode.h"
> #include "avformat.h"
> #include "internal.h"
> @@ -2159,7 +2160,7 @@ fail_and_free:
>     return ret;
> }
> 
> -static int mxf_timestamp_to_str(uint64_t timestamp, char **str)
> +static int64_t mxf_timestamp_to_int64(uint64_t timestamp)
> {
>     struct tm time = { 0 };
>     time.tm_year = (timestamp >> 48) - 1900;
> @@ -2178,13 +2179,7 @@ static int mxf_timestamp_to_str(uint64_t timestamp, char **str)
>     time.tm_min  = av_clip(time.tm_min,  0, 59);
>     time.tm_sec  = av_clip(time.tm_sec,  0, 59);
> 
> -    *str = av_mallocz(32);
> -    if (!*str)
> -        return AVERROR(ENOMEM);
> -    if (!strftime(*str, 32, "%Y-%m-%d %H:%M:%S", &time))
> -        (*str)[0] = '\0';
> -
> -    return 0;
> +    return (int64_t)av_timegm(&time) * 1000000;
> }
> 
> #define SET_STR_METADATA(pb, name, str) do { \
> @@ -2202,9 +2197,8 @@ static int mxf_timestamp_to_str(uint64_t timestamp, char **str)
> 
> #define SET_TS_METADATA(pb, name, var, str) do { \
>     var = avio_rb64(pb); \
> -    if ((ret = mxf_timestamp_to_str(var, &str)) < 0) \
> +    if ((ret = avpriv_dict_set_timestamp(&s->metadata, name, mxf_timestamp_to_int64(var)) < 0)) \
>         return ret; \
> -    av_dict_set(&s->metadata, name, str, AV_DICT_DONT_STRDUP_VAL); \
> } while (0)
> 
> static int mxf_read_identification_metadata(void *arg, AVIOContext *pb, int tag, int size, UID _uid, int64_t klv_offset)
> diff --git a/libavformat/version.h b/libavformat/version.h
> index 47a8afb..6e23f74 100644
> --- a/libavformat/version.h
> +++ b/libavformat/version.h
> @@ -33,7 +33,7 @@
> // Also please add any ticket numbers that you belive might be affected here
> #define LIBAVFORMAT_VERSION_MAJOR  57
> #define LIBAVFORMAT_VERSION_MINOR  41
> -#define LIBAVFORMAT_VERSION_MICRO 100
> +#define LIBAVFORMAT_VERSION_MICRO 101
> 
> #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
>                                                LIBAVFORMAT_VERSION_MINOR, \
> -- 
> 2.6.6
>
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