29 août

Newest 'ffmpeg' Questions - Stack Overflow http://stackoverflow.com/questions/tagged/ffmpeg

• 01:23
  I want to add a watermark using ffmpeg's cuda, but every time I try the filter in the configuration, the filter doesn't work [closed] - Maeve Newest 'ffmpeg' Questions - Stack Overflow
  AVFilterGraph* filter_graph = avfilter_graph_alloc(); char filter_desc[2048]; snprintf(filter_desc, sizeof(filter_desc), "buffer=video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:frame_rate=%d/%d[in];" "color=color=blackⓐ0:size=200x50[bg];" "[bg]drawtext=text='%s':" "fontfile='%s':" "fontsize=24:" "fontcolor=whiteⓐ0.8:" "box=1:" "boxcolor=blackⓐ0.5:" "x=10:y=10[watermark_text];" "[watermark_text]hwupload_cuda[watermark];" "[in][watermark]overlay_cuda=x=10:y=10[out];"  (...)
• 16:00
  Preserving alpha when re-encoding VP8/VP9 WebM in FFmpeg without specifying input codec - mstyura Newest 'ffmpeg' Questions - Stack Overflow
  I'm trying to understand why re-encoding a VP8 or VP9 WebM with alpha channel produces black pixels instead of preserving transparency. I simplified the problem to re-encoding VP8 with alpha to VP9 with alpha: ffmpeg -i video-vp8-with-alpha.webm -c:v libvpx-vp9 video-vp8-with-alpha-bad.webm The output loses the alpha channel. ffprobe shows: Input #0, matroska,webm, from 'video-vp8-with-alpha-bad.webm': Metadata: ENCODER : Lavf62.1.103 Duration: 00:00:03.07, start: 0.017000, bitrate: 152 kb/s Stream #0:0: Video: vp9 (Profile 0), (...) -- 0828a3b636, BtbN/FFmpeg-Builds
• 09:17
  Using FFmpegFrameRecorder using bytedeco/javavc, joining together specific parts of a video causes audio and image to fall out of sync - Tomer Shahar Newest 'ffmpeg' Questions - Stack Overflow
  I am taking a video file representing a live stream vod of several ours, I am trying to create an output file that is a few minutes of highlights taken from different parts of the video (that I let the streamer choose). I want to preserve quality as much as possible. For the most part this works, but with every jump to a new section in the VOD, I'm noticing a bigger and bigger gap forming between audio and video, falling out of sync in the output. I notice that some vods have imperfect framerate (59.998 or something of that sort) but I have been trying to adjust it in my (...)