Thanks for the reply. If pix_fmt=0 does not work, what are the other pixel formats that I can use to achieve my requirement?
>>atrim gets from [in1], i.e. buffer, while in the other version atrim is connected to [0:a], i.e. a abuffer. Do you think I need to use it in a similar way in the API as well? If possible, can you share a sample filter string that I could use? I tried all possible ways but with no luck. Regards, Madhukar On Fri, Oct 14, 2022 at 6:43 PM Nicolas George <geo...@nsup.org> wrote: > Sushma (12022-10-14): > > Hello All, > > > > I'm trying to use FFMPEG to slow down part of video and audio using C++ > > FFMPEG API. I was able to achieve it from the command line but however, > > argument parsing fails using api. > > > > Here is the command line input > > > > ffmpeg -i "inputvideo.mp4" -filter_complex > > > "[0:v]trim=0:2,setpts=PTS-STARTPTS[v1];[0:v]trim=2:10,setpts=2*(PTS-STARTPTS)[v2];[0:v]trim=10,setpts=PTS-STARTPTS[v3];[0:a]atrim=0:2,asetpts=PTS-STARTPTS[a1];[0:a]atrim=2:10,asetpts=PTS-STARTPTS,atempo=0.5[a2];[0:a]atrim=10,asetpts=PTS-STARTPTS[a3];[v1][a1][v2][a2][v3][a3]concat=n=3:v=1:a=1" > > -preset superfast -profile:v baseline output.mp4 > > > > Here is the filter string i used in avfilter_graph_parse() > > > > > buffer=video_size=1920x1080:pix_fmt=0:time_base=1/30:pixel_aspect=0/1:frame_rate=30/1 > > [in_1]; [in_1] trim = 0:2, setpts = PTS - STARTPTS [in_2]; [in_2] trim = > > 2:10, setpts = 2 * (PTS - STARTPTS)[in_3]; [in_3] trim = 10, setpts = > PTS - > > STARTPTS[in_4]; [in_1] atrim = 0:2, asetpts = PTS - STARTPTS[in_5]; > [in_5] > > atrim = 2:10, asetpts = PTS - STARTPTS, atempo = 0.5[in_6]; [in_6] atrim > = > > 10, asetpts = PTS - STARTPTS[in_7]; [in_1] [in_2] [in_5] [in_3] [in_6] > > [in_4] [in_7] concat = n = 3:v = 1 : a = 1 [result]; [result] buffersink > > > > Can anyone let me know where I'm wrong? What changes do I need to make in > > the filter string? Kindly help > > I see several issues: > > pix_fmt=0 will probably not work. > > atrim gets from [in1], i.e. buffer, while in the other version atrim is > connected to [0:a], i.e. a abuffer. > > You have several pads that are connected multiple times. > > Regards, > > -- > Nicolas George > _______________________________________________ > Libav-user mailing list > Libav-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/libav-user > > To unsubscribe, visit link above, or email > libav-user-requ...@ffmpeg.org with subject "unsubscribe". >
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