[FFmpeg-devel] [PATCH] ffmpeg: Support copying unknown streams

[Alex Beregszaszi]

Michael Niedermayer wrote:
> On Thu, May 21, 2015 at 10:20:46AM +0200, wm4 wrote:
>> On Thu, 21 May 2015 00:40:41 +0200
>> Michael Niedermayer<michaelni at gmx.at>  wrote:
>>
>>> Signed-off-by: Michael Niedermayer<michaelni at gmx.at>
>>> ---
>>>   ffmpeg.c     |    1 +
>>>   ffmpeg_opt.c |   14 ++++++++++++++
>>>   2 files changed, 15 insertions(+)
>>>
>>> diff --git a/ffmpeg.c b/ffmpeg.c
>>> index a89ae39..da3ab91 100644
>>> --- a/ffmpeg.c
>>> +++ b/ffmpeg.c
>>> @@ -2822,6 +2822,7 @@ static int transcode_init(void)
>>>                   enc_ctx->width  = dec_ctx->width;
>>>                   enc_ctx->height = dec_ctx->height;
>>>                   break;
>>> +            case AVMEDIA_TYPE_UNKNOWN:
>>>               case AVMEDIA_TYPE_DATA:
>>>               case AVMEDIA_TYPE_ATTACHMENT:
>>>                   break;
>>> diff --git a/ffmpeg_opt.c b/ffmpeg_opt.c
>>> index a8d433e..4b783a5 100644
>>> --- a/ffmpeg_opt.c
>>> +++ b/ffmpeg_opt.c
>>> @@ -1565,6 +1565,19 @@ static OutputStream *new_data_stream(OptionsContext *o, AVFormatContext *oc, int
>>>       return ost;
>>>   }
>>>
>>> +static OutputStream *new_unknown_stream(OptionsContext *o, AVFormatContext *oc, int source_index)
>>> +{
>>> +    OutputStream *ost;
>>> +
>>> +    ost = new_output_stream(o, oc, AVMEDIA_TYPE_UNKNOWN, source_index);
>>> +    if (!ost->stream_copy) {
>>> +        av_log(NULL, AV_LOG_FATAL, "Unknown stream encoding not supported yet (only streamcopy)\n");
>>> +        exit_program(1);
>>> +    }
>>> +
>>> +    return ost;
>>> +}
>>> +
>>>   static OutputStream *new_attachment_stream(OptionsContext *o, AVFormatContext *oc, int source_index)
>>>   {
>>>       OutputStream *ost = new_output_stream(o, oc, AVMEDIA_TYPE_ATTACHMENT, source_index);
>>> @@ -2016,6 +2029,7 @@ loop_end:
>>>                   case AVMEDIA_TYPE_AUDIO:      ost = new_audio_stream     (o, oc, src_idx); break;
>>>                   case AVMEDIA_TYPE_SUBTITLE:   ost = new_subtitle_stream  (o, oc, src_idx); break;
>>>                   case AVMEDIA_TYPE_DATA:       ost = new_data_stream      (o, oc, src_idx); break;
>>> +                case AVMEDIA_TYPE_UNKNOWN:    ost = new_unknown_stream   (o, oc, src_idx); break;
>>>                   case AVMEDIA_TYPE_ATTACHMENT: ost = new_attachment_stream(o, oc, src_idx); break;
>>>                   default:
>>>                       av_log(NULL, AV_LOG_FATAL, "Cannot map stream #%d:%d - unsupported type.\n",
>> Doesn't this raise the risk of creating invalid files?
>
> i dont know
> ive posted a patch that would require the user to explicitly enable
> copying unknown streams, if you prefer that ?

Probably it makes much more sense to require explicit confirmation from 
the user than doing automatically.  What kind of formats can have 
unknown streams anyway?

Best,
Alex