Recherche avancée

Sur d’autres sites (5484)

• ffmpeg video slides vertically after 'Invalid buffer size, packet size expected frame_size' error (vsync screen tearing glitch) ?

  7 juillet 2020, par GlabbichRulz

  I have a video which i want to cut and crop using opencv and ffmpeg.

  


  

  


  I want the output to be H265, so i am using a ffmpeg subprocess (writing frame bytes to stdin) as explained here. This is a minimum version of my code that leads to the error :

  


  import os, shlex, subprocess, cv2, imutils

VIDEO_DIR = '../SoExample' # should contain a file 'in.mpg'
TIMESPAN = (3827, 3927)  # cut to this timespan (frame numbers)
CROP = dict(min_x=560, max_x=731, min_y=232, max_y=418)  # crop to this area

#  calculate output video size
size = (CROP['max_x']-CROP['min_x'], CROP['max_y']-CROP['min_y'])  # (w,h)
# ffmpeg throws an error when having odd dimensions that are not dividable by 2,
# so i just add a pixel to the size and stretch the original image by 1 pixel later.
size_rounded = (size[0]+1 if size[0] % 2 != 0 else size[0],
                size[1]+1 if size[1] % 2 != 0 else size[1])

# read input video
vid_path_in = os.path.join(VIDEO_DIR, 'in.mpg')
cap = cv2.VideoCapture(vid_path_in)
fps = int(cap.get(cv2.CAP_PROP_FPS))

# generate and run ffmpeg command
ffmpeg_cmd = (f'/usr/bin/ffmpeg -y -s {size_rounded[0]}x{size_rounded[1]} -pixel_format'
              + f' bgr24 -f rawvideo -r {fps} -re -i pipe: -vcodec libx265 -pix_fmt yuv420p'
              + f' -crf 24 -x265-params "ctu=64" "{os.path.join(VIDEO_DIR, "out.mp4")}"')
print("using cmd", ffmpeg_cmd)
process = subprocess.Popen(shlex.split(ffmpeg_cmd), stdin=subprocess.PIPE)

# seek to the beginning of the cutting timespan and loop through frames of input video
cap.set(cv2.CAP_PROP_POS_FRAMES, TIMESPAN[0])
frame_returned = True
while cap.isOpened() and frame_returned:
    frame_returned, frame = cap.read()
    frame_number = cap.get(cv2.CAP_PROP_POS_FRAMES) - 1

    # check if timespan end is not reached yet
    if frame_number < TIMESPAN[1]:

        # crop to relevant image area
        frame_cropped = frame[CROP['min_y']:CROP['max_y'],
                              CROP['min_x']:CROP['max_x']]

        # resize to even frame size if needed:
        if size != size_rounded:
            frame_cropped = imutils.resize(frame_cropped, width=size_rounded[0],
                                           height=size_rounded[1])

        # Show processed image using opencv: I see no errors here.
        cv2.imshow('Frame', frame_cropped)

        # Write cropped video frame to input stream of ffmpeg sub-process.
        process.stdin.write(frame_cropped.tobytes())
    else:
        break

    # Press Q on keyboard to exit earlier
    if cv2.waitKey(25) & 0xFF == ord('q'):
        break

process.stdin.close()  # Close and flush stdin
process.wait()         # Wait for sub-process to finish
process.terminate()    # Terminate the sub-process

print("Done!")


  


  Unfortunately, my output looks like this :

  


  

  


  The output should not include this vertical sliding glitch. Does anyone know how to fix it ?

  


  My console output for aboves script shows :

  


  using cmd /usr/bin/ffmpeg -y -s 172x186 -pixel_format bgr24 -f rawvideo -r 23 -i pipe: -vcodec libx265 -pix_fmt yuv420p -crf 24 -x265-params "ctu=64" "../SoExample/out.mp4"
ffmpeg version 3.4.6-0ubuntu0.18.04.1 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 7 (Ubuntu 7.3.0-16ubuntu3)
  configuration: --prefix=/usr --extra-version=0ubuntu0.18.04.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  WARNING: library configuration mismatch
  avcodec     configuration: --prefix=/usr --extra-version=0ubuntu0.18.04.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared --enable-version3 --disable-doc --disable-programs --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libtesseract --enable-libvo_amrwbenc
  libavutil      55. 78.100 / 55. 78.100
  libavcodec     57.107.100 / 57.107.100
  libavformat    57. 83.100 / 57. 83.100
  libavdevice    57. 10.100 / 57. 10.100
  libavfilter     6.107.100 /  6.107.100
  libavresample   3.  7.  0 /  3.  7.  0
  libswscale      4.  8.100 /  4.  8.100
  libswresample   2.  9.100 /  2.  9.100
  libpostproc    54.  7.100 / 54.  7.100
Input #0, rawvideo, from 'pipe:':
  Duration: N/A, start: 0.000000, bitrate: 17659 kb/s
    Stream #0:0: Video: rawvideo (BGR[24] / 0x18524742), bgr24, 172x186, 17659 kb/s, 23 tbr, 23 tbn, 23 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> hevc (libx265))
x265 [info]: HEVC encoder version 2.6
x265 [info]: build info [Linux][GCC 7.2.0][64 bit] 8bit+10bit+12bit
x265 [info]: using cpu capabilities: MMX2 SSE2Fast LZCNT SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
x265 [info]: Main profile, Level-2 (Main tier)
x265 [info]: Thread pool created using 4 threads
x265 [info]: Slices                              : 1
x265 [info]: frame threads / pool features       : 2 / wpp(3 rows)
x265 [warning]: Source height < 720p; disabling lookahead-slices
x265 [info]: Coding QT: max CU size, min CU size : 64 / 8
x265 [info]: Residual QT: max TU size, max depth : 32 / 1 inter / 1 intra
x265 [info]: ME / range / subpel / merge         : hex / 57 / 2 / 2
x265 [info]: Keyframe min / max / scenecut / bias: 23 / 250 / 40 / 5.00
x265 [info]: Lookahead / bframes / badapt        : 20 / 4 / 2
x265 [info]: b-pyramid / weightp / weightb       : 1 / 1 / 0
x265 [info]: References / ref-limit  cu / depth  : 3 / on / on
x265 [info]: AQ: mode / str / qg-size / cu-tree  : 1 / 1.0 / 32 / 1
x265 [info]: Rate Control / qCompress            : CRF-24.0 / 0.60
x265 [info]: tools: rd=3 psy-rd=2.00 rskip signhide tmvp strong-intra-smoothing
x265 [info]: tools: deblock sao
Output #0, mp4, to '../SoExample/out.mp4':
  Metadata:
    encoder         : Lavf57.83.100
    Stream #0:0: Video: hevc (libx265) (hev1 / 0x31766568), yuv420p, 172x186, q=2-31, 23 fps, 11776 tbn, 23 tbc
    Metadata:
      encoder         : Lavc57.107.100 libx265
[rawvideo @ 0x564ebd221aa0] Invalid buffer size, packet size 51600 < expected frame_size 95976    
Error while decoding stream #0:0: Invalid argument
frame=  100 fps= 30 q=-0.0 Lsize=      36kB time=00:00:04.21 bitrate=  69.1kbits/s speed=1.25x    
video:32kB audio:0kB subtitle:0kB other streams:0kB global headers:2kB muxing overhead: 12.141185%
x265 [info]: frame I:      1, Avg QP:22.44  kb/s: 179.77  
x265 [info]: frame P:     29, Avg QP:24.20  kb/s: 130.12  
x265 [info]: frame B:     70, Avg QP:29.99  kb/s: 27.82   
x265 [info]: Weighted P-Frames: Y:0.0% UV:0.0%
x265 [info]: consecutive B-frames: 20.0% 3.3% 16.7% 43.3% 16.7% 

encoded 100 frames in 3.35s (29.83 fps), 59.01 kb/s, Avg QP:28.23
Done!


  


  As you can see, there is an error : Invalid buffer size, packet size 51600 < expected frame_size 95976 Error while decoding stream #0:0: Invalid argument, do you think this could be the cause to the shown problem ? I am not sure, as in the end, it tells me all 100 frames would have been encoded.

  


  In case you want to reproduce this on the exact same video, you can find actions1.mpg in the UCF Aerial Action Dataset.

  


  I would greatly appreciate any help as i am really stuck on this error.

  


• Libav Transcoding to H264 : Frames being dropped

  21 juin 2014, par roman

  I’m sorry if my question isn’t too well formulated, I’m only now getting started with FFmpeg and Libav. I’m not too knowledgable about media formats either, I pretty much learned all I know about the topic this past month. I’ve been doing as much research as I can, and have gotten pretty far, but I’ve only now gotten to the point where I’m almost unsure what my question actually is ! These are more like observations, but hopefully some of the experts can help me out here.

  I’m trying to transcode Gifs into MP4s using FFmpeg’s libraries, but I’m running into a strange issue when using the H264 Codec. In my transcoding loop, I keep a count of the number of frames that I write out (by verifying the return value of av_write_frame). In a particular sample, I count a total of 166 frames written out. If I examine FFmpeg’s converted file using FFprobe (the functionality I’m wanting to emulate using my program, a conversion from Gif to MP4), FFmpeg’s output file also seems to have 166 frames, but when I examine my output with FFprobe, I seem to only have 144 frames. What I find a bit interesting is that if I simply change my codec from H264 to MPEG4, my output appears to have the 166 frames, matching FFmpeg’s output and my counter. I get very similar results with different Gif files, where my counter of frames written matches FFmpeg’s output’s frame count, but my output seems to drop some frames.

  Encoder settings :

  ostream_codec_context->codec_id = CODEC_IN_USE;  //CODEC_ID_H264 or CODEC_ID_MPEG4
  
  ostream_codec_context->pix_fmt = AV_PIX_FMT_YUV420P;
  
  ostream_codec_context->codec_type = AVMEDIA_TYPE_VIDEO;
  
  ostream_codec_context->flags = CODEC_FLAG_GLOBAL_HEADER;
  
  ostream_codec_context->profile = FF_PROFILE_MPEG4_SIMPLE;
  
  
  
  ostream_codec_context->gop_size = istream_codec_context->gop_size;
  
  ostream_codec_context->time_base = istream_codec_context->time_base;
  
  
  
  ostream_codec_context->width  = (istream_codec_context->width  / 2) * 2;
  
  ostream_codec_context->height = (istream_codec_context->height / 2) * 2;    

  Transcoding loop :

  I’ve omitted some error-checking code and debugging statements

  avformat_write_header(oformat_context, NULL);
  
  while (av_read_frame(iformat_context, &packet) == 0 ) 
  
  {
  
     if (packet.stream_index == istream_index) 
  
     {   
  
        avcodec_decode_video2(istream_codec_context, ipicture, &full_frame, &packet);
  
        if (full_frame) 
  
        {
  
           sws_scale(image_conversion_context, 
  
                     (uint8_t const * const *) ipicture->data,
  
                     ipicture->linesize, 0, istream_codec_context->height,
  
                     opicture->data, opicture->linesize);
  
  
  
           opicture->pts = av_rescale_q(packet.pts, istream_codec_context->time_base,
  
                                        ostream->time_base);
  
  
  
           ret = avcodec_encode_video2(ostream_codec_context, &packet, 
  
                                       opicture, &got_packet);
  
           if (!ret)
  
           {
  
              ret = av_write_frame(oformat_context, &packet);
  
              if (ret < 0)
  
                 num_frames_written++;
  
           }
  
        }
  
     }
  
     av_free_packet(&packet);
  
     av_init_packet(&packet);
  
  }

  I’m also having issues with my output’s bit-rate. I can try setting it with the rest of my encoder settings, but the bit-rate that FFprobe shows is not the same as what I give the codec context. I tried setting the bit-rate to constant values just to see how it affected my output, and although my output’s bit-rate isn’t the same as what I give it, I found that my input definitely seems to influence the output’s actual bit-rate. I found a post that seems to be dealing with my issue, but the solution listed there does not seem to fix my issue.

  http://ffmpeg.org/pipermail/libav-user/2012-July/002492.html

  Another thing worth mentioning is that my various time bases don’t seem to match up with those of FFmpeg’s output. Notably, my output’s TBC seems to be twice the inverse of my output codec context’s time base. I’m not too sure if this is an issue with the Gif file format, my output codec context’s always seems to be set to 1/100.

  Bit-rate calculation and setting

  int calculated_br = istream_codec_context->time_base.den *     
  
                      avpicture_get_size(AV_PIX_FMT_YUV420P, ostream_codec_context->width, 
  
                                         ostream_codec_context->height);    
  
  
  
  ostream_codec_context->bit_rate = calculated_br;
  
  ostream_codec_context->rc_min_rate = calculated_br;
  
  ostream_codec_context->rc_max_rate = calculated_br;
  
  ostream_codec_context->rc_buffer_size = calculated_br;

  I’ve got a hunch that all these issues could be related to me not setting my PTS/DTS correctly, even though my output’s pts/dts values match those of FFmpeg’s output.

  I would appreciate some help,
  Thank you !

• Revision cdc954fdc8 : skip the un-necessary motion search in the first pass This patch allows the VP9

  16 juin 2014, par Pengchong Jin

  Changed Paths :
   Modify /vp9/encoder/vp9_firstpass.c

  
  
  skip the un-necessary motion search in the first pass

  This patch allows the VP9 encoder to skip the un-necessary
  motion search in the first pass. It computes the motion error
  of 0,0 motion using the last source frame as the reference,
  and skips the further motion search if this error is small.

  Borg test shows overall the patch gives PSNR gain (derf -0.001%,
  yt 0.341%, hd 0.282%). Individual clips may have PSNR gain or
  loss. The best PSNR performance is 7.347% and the worst is -0.662%.
  The first pass encoding speedup for slideshow clips is over 30%.

  Change-Id : I4cac4dbd911f277ee858e161f3ca652c771344fe