[FFmpeg-devel] [PATCH]lavf/mov: Export vendor metadata

[Carl Eugen Hoyos]

2017-01-26 0:19 GMT+01:00 Hendrik Leppkes <h.leppkes at gmail.com>:
> On Thu, Jan 26, 2017 at 10:04 AM, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>> 2017-01-25 14:22 GMT+01:00 wm4 <nfxjfg at googlemail.com>:
>>> On Mon, 12 Dec 2016 12:12:37 +0100
>>> Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
>>>
>>>> From 7c26220a8734fe7dc293efe6c13e3baf91defc7e Mon Sep 17 00:00:00 2001
>>>> From: Carl Eugen Hoyos <cehoyos at ag.or.at>
>>>> Date: Mon, 12 Dec 2016 12:07:27 +0100
>>>> Subject: [PATCH 2/2] lavf/mov: Export vendor metadata.
>>>>
>>>> ---
>>>>  libavformat/mov.c         |    5 ++++-
>>>>  tests/ref/fate/mov-zombie |    2 +-
>>>>  2 files changed, 5 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/libavformat/mov.c b/libavformat/mov.c
>>>> index 0b1c182..a19ebbf 100644
>>>> --- a/libavformat/mov.c
>>>> +++ b/libavformat/mov.c
>>>> @@ -1842,6 +1842,7 @@ static void mov_parse_stsd_video(MOVContext *c, AVIOContext *pb,
>>>>                                   AVStream *st, MOVStreamContext *sc)
>>>>  {
>>>>      uint8_t codec_name[32] = { 0 };
>>>> +    uint8_t vendor[5] = { 0 };
>>>>      int64_t stsd_start;
>>>>      unsigned int len;
>>>>
>>>> @@ -1851,7 +1852,9 @@ static void mov_parse_stsd_video(MOVContext *c, AVIOContext *pb,
>>>>
>>>>      avio_rb16(pb); /* version */
>>>>      avio_rb16(pb); /* revision level */
>>>> -    avio_rb32(pb); /* vendor */
>>>> +    avio_read(pb, vendor, 4);
>>>> +    if (vendor[0])
>>>> +        av_dict_set(&st->metadata, "vendor", vendor, 0);
>>>
>>> Does this mean transcoding to a format with per-stream
>>> tags will add this as a tag?
>>
>> The patch you quoted allows libavformat users to read the
>> vendor tag from mov files, I don't understand how it adds
>> tags.
>> Do you object?
>
> Any metadata you export can and will get copied to a new file when
> remuxing, therefor exporting arbitrary info that isn't actual stream
> metadata tags in metadata is problematic - it carries over to the
> destination file, in which it would be entirely meaningless.

Sorry, I don't understand:
Which application do you mean?

Carl Eugen