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  • ffmpeg Bmp to yuv : Crash at sws_scale

    28 décembre 2015, par the-owner

    The context :
    I have a succession of continuous bitmap and I want to encode them into a light video format.
    I use ffmpeg version 2.8.3 (the build here), under qt5, qt IDE, and msvc2013 for win32.

    The problem :
    My code crash at sws_scale () (and sometimes at avcodec_encode_video2()). When I explore the stack, the crash event occurs at sws_getCachedContext (). (I can only see the stack with these ffmpeg builds).
    I only use these ffmpeg libraries (from the Qt .pro file) :

    LIBS += -lavcodec -lavformat -lswscale -lavutil

    It’s swscale which bug. And this is the code :

    void newVideo ()
    
{
    
    ULONG_PTR gdiplusToken;
    
    GdiplusStartupInput gdiplusStartupInput;
    
    GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
    

    
    initBitmap (); //init bmp
    
    int screenWidth =  bmp.bmiHeader.biWidth;
    
    int screenHeight = bmp.bmiHeader.biHeight;
    

    
    AVCodec * codec;
    
    AVCodecContext * c = NULL;
    
    uint8_t * outbuf;
    
    int i, out_size, outbuf_size;
    

    

    
    avcodec_register_all();
    

    
    qDebug () << "Video encoding\n";
    

    
    // Find the mpeg1 video encoder
    
    codec = avcodec_find_encoder(AV_CODEC_ID_H264);
    
    if (!codec)
    
    {
    
        qDebug () << "Codec not found\n";
    
        avcodec_close(c);
    
        av_free(c);
    
        return;
    
    }
    
    else
    
        qDebug () << "H264 codec found\n";
    

    
    c = avcodec_alloc_context3(codec);
    

    
    c->bit_rate = 1000000;
    
    c->width = 800; // resolution must be a multiple of two (1280x720),(1900x1080),(720x480)
    
    c->height = 600;
    
    c->time_base.num = 1; // framerate numerator
    
    c->time_base.den = 25; // framerate denominator
    
    c->gop_size = 30; // emit one intra frame every ten frames
    
    c->max_b_frames = 1; // maximum number of b-frames between non b-frames
    
    c->pix_fmt = AV_PIX_FMT_YUV420P; //Converstion RGB to YUV ?
    
    c->codec_id = AV_CODEC_ID_H264;
    

    
    struct SwsContext* fooContext = sws_getContext(screenWidth, screenHeight,
    
                                                   AV_PIX_FMT_RGB32,
    
                                                   c->width, c->height,
    
                                                   AV_PIX_FMT_YUV420P,
    
                                                   SWS_FAST_BILINEAR,
    
                                                   NULL, NULL, NULL);
    

    
    // Open the encoder
    
    if (avcodec_open2(c, codec, NULL) < 0)
    
    {
    
        qDebug () << "Could not open codec\n";
    
        avcodec_close(c);
    
        av_free(c);
    
        return;
    
    }
    
    else qDebug () << "H264 codec opened\n";
    

    
    outbuf_size = 100000 + c->width*c->height*(32>>3);//*(32>>3); // alloc image and output buffer
    
    outbuf = static_cast(malloc(outbuf_size));
    
    qDebug() << "Setting buffer size to: " << outbuf_size << "\n";
    

    
    FILE* f = fopen("TEST.mpg","wb");
    
    if(!f) qDebug() << "x - Cannot open video file for writing\n";
    
    else qDebug() << "Opened video file for writing\n";
    

    
    // encode 5 seconds of video
    
    for (i = 0; i < STREAM_FRAME_RATE*STREAM_DURATION; i++) //the stop condition i < 5.0*5
    
    {
    
        qDebug () << "i = " << i;
    
        fflush(stdout);
    

    
        HBITMAP hBmp;
    
        if (GetScreen(hBmp) == -1) return;
    
        BYTE * pPixels;// = new BYTE [bmp.bmiHeader.biSizeImage];
    
        pPixels = getPixels (hBmp);
    
        DeleteObject (hBmp);
    

    
        int nbytes = avpicture_get_size(AV_PIX_FMT_YUV420P, c->width, c->height);
    
        uint8_t* outbuffer = (uint8_t*)av_malloc(nbytes*sizeof(uint8_t));
    
        if(!outbuffer) // check if(outbuf) instead
    
        {
    
            qDebug () << "Bytes cannot be allocated";
    
            return;
    
        }
    

    
        AVFrame* inpic = avcodec_alloc_frame(); //av_frame_alloc () ?
    
        AVFrame* outpic = avcodec_alloc_frame();
    

    
        outpic->pts = (int64_t)((float)i * (1000.0/((float)(c->time_base.den))) * 90);
    
        if (avpicture_fill((AVPicture*) inpic, (uint8_t*) pPixels, AV_PIX_FMT_RGB32,
    
                       screenWidth, screenHeight) < 0)
    
            qDebug () <<  "avpicture_fill Fill picture with image failed"; //Fill picture with image
    

    
        if(avpicture_fill((AVPicture*) outpic, outbuffer, AV_PIX_FMT_YUV420P,
    
                       c->width, c->height) < 0)
    
            qDebug () <<  "avpicture_fill failed";
    

    
        if (av_image_alloc(outpic->data, outpic->linesize, c->width, c->height,
    
                       c->pix_fmt, 1) < 0)
    
            qDebug () <<  "av_image_alloc failed";
    

    
        inpic->data[0] += inpic->linesize[0]*(screenHeight - 1); // Flipping frame
    
        inpic->linesize[0] = -inpic->linesize[0]; // Flipping frame
    

    
////////////////////////////HERE THE BUG////////////////////////////////
    
        sws_scale(fooContext,
    
                  inpic->data, inpic->linesize,
    
                  0, c->height,
    
                  outpic->data, outpic->linesize); //HERE THE BUG
    

    
        av_free_packet((AVPacket *)outbuf);
    
        // encode the image
    
        out_size = avcodec_encode_video2 (c, (AVPacket *) outbuf,
    
                                          (AVFrame *) outbuf_size, (int *) outpic);
    
///////////////////////THE CODE DONT GO BEYOND/////////////////////////////////
    

    
        qDebug () << "Encoding frame" << i <<" (size=" << out_size <<"\n";
    
        fwrite(outbuf, 1, out_size, f);
    
        delete [] pPixels;
    
        av_free(outbuffer);
    
        av_free(inpic);
    
        av_freep(outpic);
    
    }
    

    
    // get the delayed frames
    
    for(; out_size; i++)
    
    {
    
        fflush(stdout);
    
        out_size = avcodec_encode_video2 (c, (AVPacket *) outbuf,
    
                                          (AVFrame *) outbuf_size, NULL);
    
        qDebug () << "Writing frame" << i <<" (size=" << out_size <<"\n";
    
        fwrite(outbuf, 1, out_size, f);
    
    }
    

    
    // add sequence end code to have a real mpeg file
    
    outbuf[0] = 0x00;
    
    outbuf[1] = 0x00;
    
    outbuf[2] = 0x01;
    
    outbuf[3] = 0xb7;
    
    fwrite(outbuf, 1, 4, f);
    
    fclose(f);
    

    
    avcodec_close(c);
    
    free(outbuf);
    
    av_free(c);
    
    qDebug () << "Closed codec and Freed\n";
    
}

    And the output :

    Video encoding
    

    
H264 codec found
    

    
H264 codec opened
    

    
Setting buffer size to:  2020000 
    

    
Opened video file for writing
    

    
i =  0
    
**CRASH**

    I have thougth that my bitmap wasn’t good so I have crafted a bitmap just for testing, the code was :

        uint8_t* pPixels = new uint8_t[Width * 3 * Height];
    
    int x = 50;
    
    for(unsigned int i = 0; i < Width * 3 * Height; i = i + 3) // loop for generating color changing images
    
    {
    
        pPixels [i] = x % 255; //R
    
        pPixels [i + 1] = (x) % 255; //G
    
        pPixels [i + 2] = (255 - x) % 255; //B
    
    }

    However the crash continue. Perhaps, it might prove that it’s not the bitmap (pPixels) which has a problem.

    If anyone know, why I get this bug : Maybe don’t I set one parameter well ? Or one ffmpeg deprecated function ? etc.

    EDIT 1 27/12/15

    Thanks to Ronald S. Bultje The function sws_scale () does not crash with this code, however I get an error from it bad dst image pointers. My code :

    //DESTINATION FRAME            
    
if (avpicture_alloc ((AVPicture*) dst_frame, AV_PIX_FMT_YUV420P, c->width, c->height) < 0)
    
            {
    
                qDebug () <<  "# avpicture_alloc failed";
    
                return;
    
            }
    
            if(avpicture_fill((AVPicture*) dst_frame, NULL, AV_PIX_FMT_YUV420P,
    
                           c->width, c->height) < 0)
    
                qDebug () <<  "avpicture_fill failed";
    
            avcodec_align_dimensions2 (c, &c->width, &c->height, dst_frame->linesize);
    

    
//SOURCE FRAME
    
            if (avpicture_fill((AVPicture*) src_frame, (uint8_t *) pPixels, AV_PIX_FMT_RGB32,
    
                               tmp_screenWidth, tmp_screenHeight) < 0)
    
                qDebug () <<  "# avpicture_fill Fill picture with image failed"; //Fill picture with image
    
            avcodec_align_dimensions2 (c, &tmp_screenWidth, &tmp_screenHeight, src_frame->linesize);
    

    
            struct SwsContext* conversionContext = sws_getContext(tmp_screenWidth,tmp_screenHeight,AV_PIX_FMT_RGB32,c->width, c->height, AV_PIX_FMT_YUV420P,SWS_FAST_BILINEAR, NULL, NULL, NULL);
    

    
            int output_Height = sws_scale(conversionContext,
    
                                          src_frame->data, src_frame->linesize,
    
                                          0, tmp_screenHeight,
    
                                          dst_frame->data, dst_frame->linesize); //return 0 -> bad dst image pointers error

    EDIT 2 28/12/15

    I have tried to follow the Ronald S. Bultje’s suggestion and now I get a bad src image pointers error, I have investigated and worked many hours but I do not find a solution. Here, there is the new snippet :

    AVFrame* src_frame = av_frame_alloc ();
    
AVFrame* dst_frame = av_frame_alloc ();
    
AVFrame* tmp_src_frame = av_frame_alloc ();
    

    
/*........I do not use them until this snippet..........*/
    
//DESTINATION
    
//avpicture_free ((AVPicture*)dst_frame);
    
avcodec_align_dimensions2 (c, &c->width, &c->height, dst_frame->linesize);
    
if (avpicture_alloc ((AVPicture*) dst_frame, AV_PIX_FMT_YUV420P, c->width, c->height) < 0)
    
{
    
    qDebug () <<  "# avpicture_alloc failed";
    
    return;
    
}
    

    
//SOURCE
    
//stride = src_frame->linesize [0] = ((((screenWidth * bitPerPixel) + 31) & ~31) >> 3); do I need to do that ?
    
//== stride - I have gotten this formula from : https://msdn.microsoft.com/en-us/library/windows/desktop/dd318229(v=vs.85).aspx
    
if (avpicture_fill((AVPicture*) src_frame, (uint8_t *) pPixels, AV_PIX_FMT_RGB32,
    
                   screenWidth, screenHeight) < 0)
    
    qDebug () <<  "# avpicture_fill Fill picture with image failed"; //Fill picture with image
    
//linesize [0] == 21760 like commented stride
    

    
//Source TO TMP Source
    
avcodec_align_dimensions2 (c, &tmp_screenWidth, &tmp_screenHeight, tmp_src_frame->linesize);
    
if (avpicture_fill((AVPicture*) tmp_src_frame, NULL, AV_PIX_FMT_RGB32,
    
                   tmp_screenWidth, tmp_screenHeight) < 0)
    
    qDebug () <<  "# avpicture_fill Fill picture with image failed"; //Fill picture with image
    

    
av_picture_copy ((AVPicture*) tmp_src_frame, (const AVPicture*) src_frame, AV_PIX_FMT_RGB32,
    
                 screenWidth, screenHeight);
    

    
struct SwsContext* conversionContext = sws_getContext(tmp_screenWidth, tmp_screenHeight,
    
                                                      AV_PIX_FMT_RGB32,
    
                                                      c->width, c->height,
    
                                                      AV_PIX_FMT_YUV420P,
    
                                                      SWS_FAST_BILINEAR,
    
                                                      NULL, NULL, NULL);
    

    
int output_Height = sws_scale(conversionContext,
    
                              tmp_src_frame->data, tmp_src_frame->linesize,
    
                              0, tmp_screenHeight,
    
                              dst_frame->data, dst_frame->linesize);
    
//ffmpeg error = bad src image pointers
    
// output_Height == 0

    EDIT 3

    For temp Picture I have done an avcode_align_dimension2() then a avpicture_alloc() for allocating memory and avpicture_fill() in order to fill the picture pointer. Below the updated code :

    //DESTINATION
    
//avpicture_free ((AVPicture*)dst_frame);
    
avcodec_align_dimensions2 (c, &c->width, &c->height, dst_frame->linesize);
    
if (avpicture_alloc ((AVPicture*) dst_frame, AV_PIX_FMT_YUV420P, c->width, c->height) < 0)
    
{
    
    qDebug () <<  "# avpicture_alloc failed";
    
    return;
    
}
    

    
//SOURCE
    
//src_frame->linesize [0] = ((((screenWidth * bpp) + 31) & ~31) >> 3);
    
//src_frame->linesize [0] = stride;
    
if (avpicture_fill((AVPicture*) src_frame, (uint8_t *) pPixels, AV_PIX_FMT_RGB32,
    
                   screenWidth, screenHeight) < 0)
    
    qDebug () <<  "# avpicture_fill Fill picture with image failed"; //Fill picture with image
    

    
//Source TO TMP Source
    
avcodec_align_dimensions2 (c, &tmp_screenWidth, &tmp_screenHeight, tmp_src_frame->linesize);
    
if (avpicture_alloc ((AVPicture*) tmp_src_frame, AV_PIX_FMT_RGB32, tmp_screenWidth, tmp_screenHeight) < 0)
    
{
    
    qDebug () <<  "# avpicture_alloc failed";
    
    return;
    
}
    
int outbuf_size = tmp_screenWidth*tmp_screenHeight*4;// alloc image and output buffer
    
outbuf = static_cast(malloc(outbuf_size));
    
if (avpicture_fill((AVPicture*) tmp_src_frame, outbuf, AV_PIX_FMT_RGB32,
    
                   tmp_screenWidth, tmp_screenHeight) < 0)
    
    qDebug () <<  "# avpicture_fill Fill picture with image failed"; //Fill picture with image
    
av_picture_copy ((AVPicture*) tmp_src_frame, (const AVPicture*) src_frame, AV_PIX_FMT_RGB32,
    
                 tmp_screenWidth, tmp_screenHeight);
    

    
struct SwsContext* conversionContext = sws_getContext(tmp_screenWidth, tmp_screenHeight,
    
                                                      AV_PIX_FMT_RGB32,
    
                                                      c->width, c->height,
    
                                                      AV_PIX_FMT_YUV420P,
    
                                                      SWS_FAST_BILINEAR,
    
                                                      NULL, NULL, NULL);
    

    
int output_Height = sws_scale(conversionContext,
    
                              tmp_src_frame->data, tmp_src_frame->linesize,
    
                              0, tmp_screenHeight,
    
                              dst_frame->data, dst_frame->linesize);

    The call stack is as follow : av_picture_copy() is called then av_image_copy() then _VEC_memcpy() then fastcopy_I() and crash ... The problem is not the dimensions (tmp_screenWidth/Height) ? (With av_picture_copy () could we copy a picture P1 with dim W1xH1 to a picture P2 with dimension W2xH2 ?)

    EDIT 4

    Crash at av_picture_copy() which call _aligned_malloc() then av_image_copy _VEC_memcpy() and fastcopy_I()

    //SOURCE
    
if (avpicture_fill((AVPicture*) src_frame, (uint8_t *) pPixels, AV_PIX_FMT_RGB32,
    
                   screenWidth, screenHeight) < 0)
    
    qDebug () <<  "# avpicture_fill Fill picture with image failed"; //Fill picture with image
    

    
//Source TO TMP Source
    
avcodec_align_dimensions2 (c, &tmp_screenWidth, &tmp_screenHeight, tmp_src_frame->linesize);
    
if (avpicture_alloc ((AVPicture*) tmp_src_frame, AV_PIX_FMT_RGB32, tmp_screenWidth, tmp_screenHeight) < 0)
    
{
    
    qDebug () <<  "# avpicture_alloc failed";
    
    return;
    
}
    
av_picture_copy ((AVPicture*) tmp_src_frame, (const AVPicture*) src_frame, AV_PIX_FMT_RGB32,
    
                 tmp_screenWidth, tmp_screenHeight);

  • FFMPEG to create an MPEG-DASH stream with VP8

    16 septembre 2019, par Kenny Worden

    I’m trying to use FFMPEG to stream a live video feed from my webcam /dev/video0. Following scattered tutorials and scarce documentation (is this a known problem for the encoding community ?) I arrived at the following bash script :

    #!/bin/bash
    

    
ffmpeg \
    
    -y \
    
    -f v4l2 \
    
        -i /dev/video0 \
    
        -s 640x480 \
    
        -input_format mjpeg \
    
        -r 24 \
    
    -map 0:0 \
    
    -pix_fmt yuv420p \
    
    -codec:v libvpx \
    
        -s 640x480 \
    
        -threads 4 \
    
        -b:v 50k \
    
        -tile-columns 4 \
    
        -frame-parallel 1 \
    
        -keyint_min 24 -g 24 \
    
    -f webm_chunk \
    
        -header "stream.hdr" \
    
        -chunk_start_index 1 \
    
    stream_%d.chk &
    

    
sleep 2
    

    
ffmpeg \
    
    -f webm_dash_manifest -live 1 \
    
    -i stream.hdr \
    
    -c copy \
    
    -map 0 \
    
    -f webm_dash_manifest -live 1 \
    
        -adaptation_sets "id=0,streams=0" \
    
        -chunk_start_index 1 \
    
        -chunk_duration_ms 1000 \
    
        -time_shift_buffer_depth 30000 \
    
        -minimum_update_period 60000 \
    
    stream_manifest.mpd

    When I run this script, my webcam light turns on, the stream.hdr and stream_manifest.mpd files are written, and chunks start to be created (i.e. stream_1.chk, stream_2.chk, etc...). However, FFMPEG throws the following error :

    Could not write header for output file #0 (incorrect codec parameters
     ?) : Invalid data found when processing input

    I will explain what I think I am doing with this script, and hopefully this will expose any errors in my thinking.

    First, we invoke FFMPEG to use Video for Linux 2 (v4l2) to read from my webcam (/dev/video0) of a resolution 640x480. The input format is mjpeg with a framerate of 24fps.

    I then declare that FFMPEG should "map" (copy) the video stream output by v4l2 to a file. I specify the pixel format (YUV420P) and use libvpx (VP8 encoding) to encode the video stream. I set the size to be 640x480, use 4 threads, set the bitrate to be 50kbps, do some magic with tile-columns and frame-parallel options, and set the I-frames to be 24 frames apart.

    I then create a stream.hdr file. The starting index is 1. This command continues to run infinitely until I kill it, grabbing new video from my webcam and outputting it into chunks.

    I then sleep for 2 seconds to give the previous command time to generate a header file.

    And that’s really it. The next invocation of FFMPEG simply creates the MPEG-DASH manifest file given the header generated in the previous step.

    So what’s going on ? Why can I not view the video in a web browser (I’m using Dash.js) ? I serve the manifest, header, and chunks on a Node.js server so that trivial issue is not the problem.

    Edit : Here is my full console output.

    ffmpeg version 3.0.7-0ubuntu0.16.10.1 Copyright (c) 2000-2017 the FFmpeg developers
    
  built with gcc 6.2.0 (Ubuntu 6.2.0-5ubuntu12) 20161005
    
  configuration: --prefix=/usr --extra-version=0ubuntu0.16.10.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --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-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librubberband --enable-librtmp --enable-libschroedinger --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-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-chromaprint --enable-libx264
    
  libavutil      55. 17.103 / 55. 17.103
    
  libavcodec     57. 24.102 / 57. 24.102
    
  libavformat    57. 25.100 / 57. 25.100
    
  libavdevice    57.  0.101 / 57.  0.101
    
  libavfilter     6. 31.100 /  6. 31.100
    
  libavresample   3.  0.  0 /  3.  0.  0
    
  libswscale      4.  0.100 /  4.  0.100
    
  libswresample   2.  0.101 /  2.  0.101
    
  libpostproc    54.  0.100 / 54.  0.100
    
[video4linux2,v4l2 @ 0x55847e244ea0] The driver changed the time per frame from 1/24 to 1/30
    
[mjpeg @ 0x55847e245c00] Changing bps to 8
    
Input #0, video4linux2,v4l2, from '/dev/video0':
    
  Duration: N/A, start: 64305.102081, bitrate: N/A
    
    Stream #0:0: Video: mjpeg, yuvj422p(pc, bt470bg/unknown/unknown), 640x480, -5 kb/s, 30 fps, 30 tbr, 1000k tbn, 1000k tbc
    
Codec AVOption frame-parallel (Enable frame parallel decodability features) specified for output file #0 (stream_%d.chk) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
    
Codec AVOption tile-columns (Number of tile columns to use, log2) specified for output file #0 (stream_%d.chk) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
    
[swscaler @ 0x55847e24b720] deprecated pixel format used, make sure you did set range correctly
    
[libvpx @ 0x55847e248a20] v1.5.0
    
Output #0, webm_chunk, to 'stream_%d.chk':
    
  Metadata:
    
    encoder         : Lavf57.25.100
    
    Stream #0:0: Video: vp8 (libvpx), yuv420p, 640x480, q=-1--1, 50 kb/s, 30 fps, 30 tbn, 30 tbc
    
    Metadata:
    
      encoder         : Lavc57.24.102 libvpx
    
    Side data:
    
      unknown side data type 10 (24 bytes)
    
Stream mapping:
    
  Stream #0:0 -> #0:0 (mjpeg (native) -> vp8 (libvpx))
    
Press [q] to stop, [?] for help
    
frame=   21 fps=0.0 q=0.0 size=N/A time=00:00:00.70 bitrate=N/A dup=5 drop=frame=   36 fps= 35 q=0.0 size=N/A time=00:00:01.20 bitrate=N/A dup=5 drop=frame=   51 fps= 33 q=0.0 size=N/A time=00:00:01.70 bitrate=N/A dup=5 drop=ffmpeg version 3.0.7-0ubuntu0.16.10.1 Copyright (c) 2000-2017 the FFmpeg developers
    
  built with gcc 6.2.0 (Ubuntu 6.2.0-5ubuntu12) 20161005
    
  configuration: --prefix=/usr --extra-version=0ubuntu0.16.10.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --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-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librubberband --enable-librtmp --enable-libschroedinger --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-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-chromaprint --enable-libx264
    
  libavutil      55. 17.103 / 55. 17.103
    
  libavcodec     57. 24.102 / 57. 24.102
    
  libavformat    57. 25.100 / 57. 25.100
    
  libavdevice    57.  0.101 / 57.  0.101
    
  libavfilter     6. 31.100 /  6. 31.100
    
  libavresample   3.  0.  0 /  3.  0.  0
    
  libswscale      4.  0.100 /  4.  0.100
    
  libswresample   2.  0.101 /  2.  0.101
    
  libpostproc    54.  0.100 / 54.  0.100
    
Input #0, webm_dash_manifest, from 'stream.hdr':
    
  Metadata:
    
    encoder         : Lavf57.25.100
    
  Duration: N/A, bitrate: N/A
    
    Stream #0:0: Video: vp8, yuv420p, 640x480, SAR 1:1 DAR 4:3, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
    
    Metadata:
    
      webm_dash_manifest_file_name: stream.hdr
    
      webm_dash_manifest_track_number: 1
    
Output #0, webm_dash_manifest, to 'stream_manifest.mpd':
    
  Metadata:
    
    encoder         : Lavf57.25.100
    
    Stream #0:0: Video: vp8, yuv420p, 640x480 [SAR 1:1 DAR 4:3], q=2-31, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
    
    Metadata:
    
      webm_dash_manifest_file_name: stream.hdr
    
      webm_dash_manifest_track_number: 1
    
Stream mapping:
    
  Stream #0:0 -> #0:0 (copy)
    
Could not write header for output file #0 (incorrect codec parameters ?): Invalid data found when processing input
    
frame=   67 fps= 33 q=0.0 size
    
frame=   82 fps= 32 q=0.0 size=N/A time=00:00:02.73 bitrate=N/A dup=5 drop=
    
frame=   97 fps= 32 q=0.0 size=N/A time=00:00:03.23 bitrate=N/A dup=5 drop=
    
frame=  112 fps= 32 q=0.0 size=N/A time=00:00:03.73 bitrate=N/A dup=5 ...

  • FFMPEG to create an MPEG-DASH stream with VP8

    24 avril 2017, par Kenneth Worden

    I’m trying to use FFMPEG to stream a live video feed from my webcam /dev/video0. Following scattered tutorials and scarce documentation (is this a known problem for the encoding community ?) I arrived at the following bash script :

    #!/bin/bash
    

    
ffmpeg \
    
    -y \
    
    -f v4l2 \
    
        -i /dev/video0 \
    
        -s 640x480 \
    
        -input_format mjpeg \
    
        -r 24 \
    
    -map 0:0 \
    
    -pix_fmt yuv420p \
    
    -codec:v libvpx \
    
        -s 640x480 \
    
        -threads 4 \
    
        -b:v 50k \
    
        -tile-columns 4 \
    
        -frame-parallel 1 \
    
        -keyint_min 24 -g 24 \
    
    -f webm_chunk \
    
        -header "stream.hdr" \
    
        -chunk_start_index 1 \
    
    stream_%d.chk &
    

    
sleep 2
    

    
ffmpeg \
    
    -f webm_dash_manifest -live 1 \
    
    -i stream.hdr \
    
    -c copy \
    
    -map 0 \
    
    -f webm_dash_manifest -live 1 \
    
        -adaptation_sets "id=0,streams=0" \
    
        -chunk_start_index 1 \
    
        -chunk_duration_ms 1000 \
    
        -time_shift_buffer_depth 30000 \
    
        -minimum_update_period 60000 \
    
    stream_manifest.mpd

    When I run this script, my webcam light turns on, the stream.hdr and stream_manifest.mpd files are written, and chunks start to be created (i.e. stream_1.chk, stream_2.chk, etc...). However, FFMPEG throws the following error :

    Could not write header for output file #0 (incorrect codec parameters
     ?) : Invalid data found when processing input

    I will explain what I think I am doing with this script, and hopefully this will expose any errors in my thinking.

    First, we invoke FFMPEG to use Video for Linux 2 (v4l2) to read from my webcam (/dev/video0) of a resolution 640x480. The input format is mjpeg with a framerate of 24fps.

    I then declare that FFMPEG should "map" (copy) the video stream output by v4l2 to a file. I specify the pixel format (YUV420P) and use libvpx (VP8 encoding) to encode the video stream. I set the size to be 640x480, use 4 threads, set the bitrate to be 50kbps, do some magic with tile-columns and frame-parallel options, and set the I-frames to be 24 frames apart.

    I then create a stream.hdr file. The starting index is 1. This command continues to run infinitely until I kill it, grabbing new video from my webcam and outputting it into chunks.

    I then sleep for 2 seconds to give the previous command time to generate a header file.

    And that’s really it. The next invocation of FFMPEG simply creates the MPEG-DASH manifest file given the header generated in the previous step.

    So what’s going on ? Why can I not view the video in a web browser (I’m using Dash.js) ? I serve the manifest, header, and chunks on a Node.js server so that trivial issue is not the problem.

    Edit : Here is my full console output.

    ffmpeg version 3.0.7-0ubuntu0.16.10.1 Copyright (c) 2000-2017 the FFmpeg developers
    
  built with gcc 6.2.0 (Ubuntu 6.2.0-5ubuntu12) 20161005
    
  configuration: --prefix=/usr --extra-version=0ubuntu0.16.10.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --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-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librubberband --enable-librtmp --enable-libschroedinger --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-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-chromaprint --enable-libx264
    
  libavutil      55. 17.103 / 55. 17.103
    
  libavcodec     57. 24.102 / 57. 24.102
    
  libavformat    57. 25.100 / 57. 25.100
    
  libavdevice    57.  0.101 / 57.  0.101
    
  libavfilter     6. 31.100 /  6. 31.100
    
  libavresample   3.  0.  0 /  3.  0.  0
    
  libswscale      4.  0.100 /  4.  0.100
    
  libswresample   2.  0.101 /  2.  0.101
    
  libpostproc    54.  0.100 / 54.  0.100
    
[video4linux2,v4l2 @ 0x55847e244ea0] The driver changed the time per frame from 1/24 to 1/30
    
[mjpeg @ 0x55847e245c00] Changing bps to 8
    
Input #0, video4linux2,v4l2, from '/dev/video0':
    
  Duration: N/A, start: 64305.102081, bitrate: N/A
    
    Stream #0:0: Video: mjpeg, yuvj422p(pc, bt470bg/unknown/unknown), 640x480, -5 kb/s, 30 fps, 30 tbr, 1000k tbn, 1000k tbc
    
Codec AVOption frame-parallel (Enable frame parallel decodability features) specified for output file #0 (stream_%d.chk) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
    
Codec AVOption tile-columns (Number of tile columns to use, log2) specified for output file #0 (stream_%d.chk) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
    
[swscaler @ 0x55847e24b720] deprecated pixel format used, make sure you did set range correctly
    
[libvpx @ 0x55847e248a20] v1.5.0
    
Output #0, webm_chunk, to 'stream_%d.chk':
    
  Metadata:
    
    encoder         : Lavf57.25.100
    
    Stream #0:0: Video: vp8 (libvpx), yuv420p, 640x480, q=-1--1, 50 kb/s, 30 fps, 30 tbn, 30 tbc
    
    Metadata:
    
      encoder         : Lavc57.24.102 libvpx
    
    Side data:
    
      unknown side data type 10 (24 bytes)
    
Stream mapping:
    
  Stream #0:0 -> #0:0 (mjpeg (native) -> vp8 (libvpx))
    
Press [q] to stop, [?] for help
    
frame=   21 fps=0.0 q=0.0 size=N/A time=00:00:00.70 bitrate=N/A dup=5 drop=frame=   36 fps= 35 q=0.0 size=N/A time=00:00:01.20 bitrate=N/A dup=5 drop=frame=   51 fps= 33 q=0.0 size=N/A time=00:00:01.70 bitrate=N/A dup=5 drop=ffmpeg version 3.0.7-0ubuntu0.16.10.1 Copyright (c) 2000-2017 the FFmpeg developers
    
  built with gcc 6.2.0 (Ubuntu 6.2.0-5ubuntu12) 20161005
    
  configuration: --prefix=/usr --extra-version=0ubuntu0.16.10.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --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-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librubberband --enable-librtmp --enable-libschroedinger --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-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-chromaprint --enable-libx264
    
  libavutil      55. 17.103 / 55. 17.103
    
  libavcodec     57. 24.102 / 57. 24.102
    
  libavformat    57. 25.100 / 57. 25.100
    
  libavdevice    57.  0.101 / 57.  0.101
    
  libavfilter     6. 31.100 /  6. 31.100
    
  libavresample   3.  0.  0 /  3.  0.  0
    
  libswscale      4.  0.100 /  4.  0.100
    
  libswresample   2.  0.101 /  2.  0.101
    
  libpostproc    54.  0.100 / 54.  0.100
    
Input #0, webm_dash_manifest, from 'stream.hdr':
    
  Metadata:
    
    encoder         : Lavf57.25.100
    
  Duration: N/A, bitrate: N/A
    
    Stream #0:0: Video: vp8, yuv420p, 640x480, SAR 1:1 DAR 4:3, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
    
    Metadata:
    
      webm_dash_manifest_file_name: stream.hdr
    
      webm_dash_manifest_track_number: 1
    
Output #0, webm_dash_manifest, to 'stream_manifest.mpd':
    
  Metadata:
    
    encoder         : Lavf57.25.100
    
    Stream #0:0: Video: vp8, yuv420p, 640x480 [SAR 1:1 DAR 4:3], q=2-31, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
    
    Metadata:
    
      webm_dash_manifest_file_name: stream.hdr
    
      webm_dash_manifest_track_number: 1
    
Stream mapping:
    
  Stream #0:0 -> #0:0 (copy)
    
Could not write header for output file #0 (incorrect codec parameters ?): Invalid data found when processing input
    
frame=   67 fps= 33 q=0.0 size
    
frame=   82 fps= 32 q=0.0 size=N/A time=00:00:02.73 bitrate=N/A dup=5 drop=
    
frame=   97 fps= 32 q=0.0 size=N/A time=00:00:03.23 bitrate=N/A dup=5 drop=
    
frame=  112 fps= 32 q=0.0 size=N/A time=00:00:03.73 bitrate=N/A dup=5 ...

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