Newest 'ffmpeg' Questions - Stack Overflow

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• FFprobe Throws JsonSyntaxException with NumberFormatException on Some Video Files [closed]

  3 avril, par Daydreamer067

  I'm using FFprobe through the Java wrapper to analyze video files:

      FFprobe ffprobe = new FFprobe("pathTo/ffprobe.exe");
      FFmpegProbeResult probeResult = ffprobe.probe(fichierTemp.getPath());
  

  This works fine for most files. However, on some video files, I get the following error:

  com.google.gson.JsonSyntaxException: java.lang.NumberFormatException: Expected an int but was 109893054318340751 at line 160 column 37 path $.chapters[0].id
  

  It seems like FFprobe is returning a chapter ID that is a long but it expected an int. How can I handle this situation and avoid this exception?

  Is there a way to customize the JSON parsing or configure FFprobe to return int values?

• Using HEVC with Alpha to Compose Moviepy Video

  3 avril, par James Grace

  I'm using moviepy, PIL and numpy and trying to compile a video with 3 components : A background image that is a PNG with no transparency, an Overlay Video that is a HEVC with Alpha, and a primary clip that is produced with a collection of PNG images with transparency.

  The video is composed with background + overlay video + main video.

  The problem I'm having is that the overlay video has a black background, so the background image is covered completely. Moviepy is able to import the HEVC video successfully by it seems as though the Alpha channel is lost on import.

  Any ideas?

  Here's my code :

  from PIL import Image
  import moviepy.editor as mpe
  import numpy as np
  
  def CompileVideo() :
  
      frames = ["list_of_png_files_with_transparency"]
      fps = 30.0
      clips = [mpe.ImageClip(np.asarray(Image.open(frame))).set_duration(1 / int(fps)) for frame in frames]
      ad_clip = mpe.concatenate_videoclips(clips, method="compose")
      bg_clip = mpe.ImageClip(np.asarray(Image.open("path_to_background_file_no_transparency"))).set_duration(ad_clip.duration)
  
      overlay_clip = mpe.VideoFileClip("path_to_HEVC_with_Alpha.mov")
  
      comp = [bg_clip, overlay_clip, ad_clip]
  
      final = mpe.CompositeVideoClip(comp).set_duration(ad_clip.duration)
      final.write_videofile("output.mp4", fps=fps)
  

• FFmpeg av_seek_frame() successful, but decoding always starts from the beginning

  3 avril, par Summit

  I'm working on a video player using FFmpeg in C++, where I need to seek to a specific PTS (timestamp) and start decoding from there. However, even after a successful av_seek_frame(), decoding always starts from frame 0 instead of the target frame.

  void decodeLoop() {
        while (!stopThread) {
  
            std::unique_lock lock(mtx);
            cv.wait(lock, [this] { return decoding || stopThread; });
  
            if (stopThread) break;
  
            int64_t reqTimestamp = requestedTimestamp.load();
  
            // **Skip redundant seeks**
            if (reqTimestamp == lastRequestedTimestamp.load()) {
                continue;  // Avoid unnecessary seeks
            }
  
            int64_t requestedTS = requestedTimestamp.load();
            AVRational stream_tb = fmt_ctx->streams[video_stream_index]->time_base;
            int64_t target_pts = reqTimestamp;
            target_pts = FFMAX(target_pts, 0); // Ensure it's not negative
  
            int seek_flags = AVSEEK_FLAG_BACKWARD;
  
            if (av_seek_frame(fmt_ctx, video_stream_index, target_pts, seek_flags) >= 0) {
                avcodec_flush_buffers(codec_ctx);  // Clear old frames from the decoder
                avformat_flush(fmt_ctx);          // **Flush demuxer**
                qDebug() << "Seek successful to PTS:" << target_pts;
         //      avfilter_graph_free(&filter_graph);  // Reset filter graph
            }
            else {
                qDebug() << "Seeking failed!";
                decoding = false;
                continue;
            }
  
            lock.unlock();
  
            // Keep decoding frames until we reach (or slightly exceed) requestedTimestamp
            bool frameDecoded = false;
            while (av_read_frame(fmt_ctx, pkt) >= 0) {
                if (pkt->stream_index == video_stream_index) {
                    if (avcodec_send_packet(codec_ctx, pkt) == 0) {
                        while (avcodec_receive_frame(codec_ctx, frame) == 0) {
                            int64_t frame_pts = frame->pts;
  
                            // Skip frames before reaching target PTS
                            if (frame_pts < requestedTimestamp.load()) {
  
                                qDebug() << "SKIPPING FRAMES " << frame_pts;
                                av_frame_unref(frame);  // Free unused frame memory
                                continue;  // Discard early frames
                            }
  
                            qDebug() << "DECODING THE SEEKED FRAMES " << frame_pts;
  
                            if (frame_pts >= requestedTimestamp.load()) {
                               
                                    // Accept frame only if it's close enough to the target PTS
                                    current_pts.store(frame_pts);
                                    lastRequestedTimestamp.store(requestedTimestamp.load());
                                    convertHWFrameToImage(frame);
                                    emit frameDecodedSignal(outputImage);
                                    frameDecoded = true;
                                    break;  // Stop decoding once we reach the desired frame
                               
                            }
                        }
                    }
                }
                av_packet_unref(pkt);
  
                if (frameDecoded) break;
            }
  
            decoding = false;
        }
    }
  

• React Native alternatives to ffmpeg-kit-react-native for adding text overlays to videos ?

  3 avril, par Sanjay Kalal

  I’m developing a React Native app where I need to add text overlays to videos. I was using ffmpeg-kit-react-native, but this library is deprecated, I am looking for efficient alternative and add overlay text on video and then share it with overlay text.

  Are there any React Native libraries or native integrations that can efficiently add text overlays to videos without using ffmpeg?

• ffmpeg loop push rtmp error with when using arg -t

  3 avril, par se7enXF

  I want to loop push a part of video, such as the start 5 senonds, by cmd: ffmpeg -re -stream_loop -1 -ss 0 -t 5 -i xxx.mp4 -c copy -f flv rtmp://xxx Run the command, after 5 senonds error raise:

  [flv @ 000001c7b4a0f040] Failed to update header with correct duration.4.7kbits/s speed=   1x
  [flv @ 000001c7b4a0f040] Failed to update header with correct filesize.
  

  It works fine if first using ffmpeg cut the video then pushing with out -t. Is there a way to do this together? Because the input file may be a file or a network stream.