Hi,dear friends, recently I have a task which need cut the long videos to many segments. The concrete code I used as follow: 1. First I convert all video to mpeg4 codec. Use [cid:image001.png@01D53569.052114F0] 2. Second I cut the video in a simple python script. Use [cid:image002.png@01D53569.647DEC70] 3. Then when I decode the video, try to extract some i-frames and MVs,I got a error.. [cid:image003.png@01D53569.F5AEF5E0] The mpeg4 header seems to be damaged. But use the potplayer to play it's ok. So I want know the problem. thanks a lot.
On Jul 7, 2019, at 8:51 PM, Hu Saijun <saijunhu@outlook.com> wrote:
Hi,dear friends, recently I have a task which need cut the long videos to many segments. The concrete code I used as follow:
1. First I convert all video to mpeg4 codec. Use [cid:image001.png@01D53569.052114F0]
2. Second I cut the video in a simple python script. Use [cid:image002.png@01D53569.647DEC70]
3. Then when I decode the video, try to extract some i-frames and MVs,I got a error.. [cid:image003.png@01D53569.F5AEF5E0]
Is there a reason for transcoding to mpeg4 and then splitting? If you transcode them as separate segments in the first place, I don’t think you will see this issue (codec copying and splitting mpeg4 might be the problem). Something like: ffmpeg -ss ${start} -to ${end} -i ${inname} -vf scale=340:256,setsar=1:1 -q:v 1 -c:v mpeg4 ${output1} and repeat for however many cuts you need to make. P.S. It’s preferable to paste the command and output as text rather attach an image of them
Well ,thanks very much ! it sounds a good idea to it together. -----邮件原件----- 发件人: ffmpeg-user <ffmpeg-user-bounces@ffmpeg.org> 代表 Ted Park 发送时间: 2019年7月8日 10:45 收件人: FFmpeg user questions <ffmpeg-user@ffmpeg.org> 主题: Re: [FFmpeg-user] Decode Error
On Jul 7, 2019, at 8:51 PM, Hu Saijun <saijunhu@outlook.com> wrote:
Hi,dear friends, recently I have a task which need cut the long videos to many segments. The concrete code I used as follow:
1. First I convert all video to mpeg4 codec. Use [cid:image001.png@01D53569.052114F0]
2. Second I cut the video in a simple python script. Use [cid:image002.png@01D53569.647DEC70]
3. Then when I decode the video, try to extract some i-frames and MVs,I got a error.. [cid:image003.png@01D53569.F5AEF5E0]
Is there a reason for transcoding to mpeg4 and then splitting? If you transcode them as separate segments in the first place, I don’t think you will see this issue (codec copying and splitting mpeg4 might be the problem). Something like: ffmpeg -ss ${start} -to ${end} -i ${inname} -vf scale=340:256,setsar=1:1 -q:v 1 -c:v mpeg4 ${output1} and repeat for however many cuts you need to make. P.S. It’s preferable to paste the command and output as text rather attach an image of them _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-request@ffmpeg.org with subject "unsubscribe".
participants (2)
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Hu Saijun -
Ted Park