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• FFmpeg live streaming for media source extensions(MSE)

  1er septembre 2022, par IceCreamVan

  I try implement video live streaming from RTSP stream to webpage with media source extensions(MSE) with using FFmpeg

  


  Expected system diagram.

  


  

  


  I know that this task can realize with HLS or WebRTC, but HLS have large delay and WebRTC very hard to implementation.

  


  I want catch RTSP stream with FFMPEG split it to ISO BMMF(ISO/IEC 14496-12) chuncks in "live mode" and send it to my web server by TCP in which i restream this chunks to webpage by websocket. In webpage i append chunck to buffer sourceBuffer.appendBuffer(new Uint8Array(chunck)) and video play in streaming mode.

  


  Problem in first step with ffmpeg i can easy split RTSP stream to segments with this

  


  ffmpeg -i test.mp4 -map 0 -c copy -f segment -segment_time 2 -reset_timestamps 1 output_%03d.mp4


  


  but i cant redirect output to tcp ://127.0.0.1 or pipe:1, if i correctly understood segment not work with pipes. For example i can easy send video frames in jpg by TCP with image2 catch ff d9 bytes in TCP stream and split stream to jpg images.

  


  ffmpeg -i rtsp://127.0.0.1:8554 -f image2pipe tcp://127.0.0.1:7400


  


  How i can split RTSP stream to ISO BMMF chunks for sending to webpage for playing with media source extensions ? Or other way to prepare RTSP stream with FFmpeg for playing in MSE. Maybe i not correctly understood how working MSE and how prepare video for playing.

  


• How to accurately/precisely seek to a timestamp in media with ffmpeg API ?

  11 novembre 2024, par wangt13

  I am writing a simple audio player with ffmpeg ver.4.4.4, and I want to seek to specific timestamp of the audio media (a MP3 file).

  


  Here is my code.
I am using avformat_seek_file() with flags of AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD, and when I set seek_pos to 10 second when it is playing frames of 3rd second, it seemed NOT jump to the 10th second, it only played the audios after 3rd second !

  


  Then I added the code skipping/discarding the packets whose pts is before the seek position. This time, it loops in the if (curr_s < seek_ts), not going to 10th seconds.

  


  It seemed NO keyframe at 10th second.

  


  void decode_func(...)
{
    while (1) {
        if (av_read_frame(pfmtctx, packet) < 0) {
            avcodec_flush_buffers(pcodectx);
            printf("Got end of media, breaking\n");
            break;
        }
        /**
         * Discard the packet of pts before seek position
         */
        curr_s = packet->pts * av_q2d(pfmtctx->streams[stream]->time_base);
        if (seek_ts) {
            if (curr_s < seek_ts) {
                avcodec_flush_buffers(pcodectx);
                av_frame_unref(pFrame);
                continue;
            } else {
                seek_ts = 0;
            }
        }
        if (seek_req) {
            int64_t seek_abs;
            seek_req = 0;
            seek_abs = (seek_pos)*AV_TIME_BASE;
            printf("Seek to %lld, pts: %lld\n", seek_abs, packet->pts;
            if (seek_abs < 0) {
                seek_abs = 0;
            }
            if (avformat_seek_file(pfmtctx, -1, INT64_MIN, seek_abs, INT64_MAX, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD) >= 0) {
                avcodec_flush_buffers(pcodectx);
                seek_ts = seek_abs;
                continue;
            } else {
                printf("Failed to seek to %lld\n", seek_abs);
                seek_ts = 0;
            }
        }

        res = avcodec_send_packet(pcodectx, packet);
        while (res >= 0) {
            res = avcodec_receive_frame(pcodectx, pFrame);
            if (res == AVERROR(EAGAIN)) {
                break;
            } else if (res == AVERROR_EOF) {
                break;
            } else if (res >= 0) {
             /// Processing decoded frame
            }
        av_frame_unref(frame);
    }
}


  


  So, how can I precisely (almost) seek to a timestamp with FFMPEG ?

  


• FFmpeg to transfer from bad media

  31 décembre 2017, par TheSavo

  I have an SDcard that has two videos recorded from an old phone. The media is bad and I have already run SpinRite and chkdsk, to fix the errors. The files still fail to copy completely.

  I can play some portion of the files in VLC player. It plays about as far as File copy and TeraCopy before the copy job fails.
  They and MP4 files. I would like to use ffmpeg to transfer the portion of the video that will play out. is -i the best parameter ?

  ffmpeg -i H:\badfile.mp4 e:\portion.mp4

  Here is the output from mediainfo if that helps

  Complete name                            : H:\DCIM\badfile.mp4
Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom (isom/3gp4)
File size                                : 422 MiB
Duration                                 : 3 min 46 s
Overall bit rate                         : 15.6 Mb/s
Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4
Format settings                          : CABAC / 1 Ref Frames
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 1 frame
Format settings, GOP                     : M=1, N=61
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 3 min 45 s
Bit rate                                 : 15.5 Mb/s
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Variable
Frame rate                               : 19.469 FPS
Minimum frame rate                       : 14.085 FPS
Maximum frame rate                       : 30.303 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.385
Stream size                              : 418 MiB (99%)
Title                                    : VideoHandle
Language                                 : English
Encoded date                             : UTC 2013-09-17 13:18:06
Tagged date                              : UTC 2013-09-17 13:18:06
mdhd_Duration                            : 225892

  Audio
  ID : 2
  Format : AAC
  Format/Info : Advanced Audio Codec
  Format profile : LC
  Codec ID : mp4a-40-2
  Duration : 3 min 46 s
  Bit rate mode : Constant
  Bit rate : 128 kb/s
  Nominal bit rate : 96.0 kb/s
  Channel(s) : 2 channels
  Channel positions : Front : L R
  Sampling rate : 44.1 kHz
  Frame rate : 43.066 FPS (1024 SPF)
  Compression mode : Lossy
  Stream size : 3.46 MiB (1%)
  Title : SoundHandle
  Language : English
  Encoded date : UTC 2013-09-17 13:18:06
  Tagged date : UTC 2013-09-17 13:18:06