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  • Video creation with a recent ffmpeg API (2017)

    16 novembre 2017, par ar2015

    I have started learning how to work with ffmpeg which has a suffering deprecation of all tutorial and available examples such as this.

    I am looking for a code which creates an output video.

    Unfortunately, most of good examples are focusing on reading from a file rather than creating one.

    Here, I have found a deprecated example and I spent a long time to fix its errors until it became like this :

    #include <iostream>
    #include
    #include
    #include <string>

    extern "C" {
           #include <libavcodec></libavcodec>avcodec.h>
           #include <libavformat></libavformat>avformat.h>
           #include <libswscale></libswscale>swscale.h>
           #include <libavformat></libavformat>avio.h>
           #include <libavutil></libavutil>opt.h>
    }

    #define WIDTH 800
    #define HEIGHT 480
    #define STREAM_NB_FRAMES  ((int)(STREAM_DURATION * FRAME_RATE))
    #define FRAME_RATE 24
    #define PIXEL_FORMAT AV_PIX_FMT_YUV420P
    #define STREAM_DURATION 5.0 //seconds
    #define BIT_RATE 400000

    #define AV_CODEC_FLAG_GLOBAL_HEADER (1 &lt;&lt; 22)
    #define CODEC_FLAG_GLOBAL_HEADER AV_CODEC_FLAG_GLOBAL_HEADER
    #define AVFMT_RAWPICTURE 0x0020

    using namespace std;

    static int sws_flags = SWS_BICUBIC;

    AVFrame *picture, *tmp_picture;
    uint8_t *video_outbuf;
    int frame_count, video_outbuf_size;


    /****** IF LINUX ******/
    inline int sprintf_s(char* buffer, size_t sizeOfBuffer, const char* format, ...)
    {
       va_list ap;
       va_start(ap, format);
       int result = vsnprintf(buffer, sizeOfBuffer, format, ap);
       va_end(ap);
       return result;
    }

    /****** IF LINUX ******/
    template
    inline int sprintf_s(char (&amp;buffer)[sizeOfBuffer], const char* format, ...)
    {
       va_list ap;
       va_start(ap, format);
       int result = vsnprintf(buffer, sizeOfBuffer, format, ap);
       va_end(ap);
       return result;
    }


    static void closeVideo(AVFormatContext *oc, AVStream *st)
    {
       avcodec_close(st->codec);
       av_free(picture->data[0]);
       av_free(picture);
       if (tmp_picture)
       {
           av_free(tmp_picture->data[0]);
           av_free(tmp_picture);
       }
       av_free(video_outbuf);
    }

    static AVFrame *alloc_picture(enum AVPixelFormat pix_fmt, int width, int height)
    {
       AVFrame *picture;
       uint8_t *picture_buf;
       int size;

       picture = av_frame_alloc();
       if(!picture)
           return NULL;
       size = avpicture_get_size(pix_fmt, width, height);
       picture_buf = (uint8_t*)(av_malloc(size));
       if (!picture_buf)
       {
           av_free(picture);
           return NULL;
       }
       avpicture_fill((AVPicture *) picture, picture_buf, pix_fmt, WIDTH, HEIGHT);
       return picture;
    }

    static void openVideo(AVFormatContext *oc, AVStream *st)
    {
       AVCodec *codec;
       AVCodecContext *c;

       c = st->codec;
       if(c->idct_algo == AV_CODEC_ID_H264)
           av_opt_set(c->priv_data, "preset", "slow", 0);

       codec = avcodec_find_encoder(c->codec_id);
       if(!codec)
       {
           std::cout &lt;&lt; "Codec not found." &lt;&lt; std::endl;
           std::cin.get();std::cin.get();exit(1);
       }

       if(codec->id == AV_CODEC_ID_H264)
           av_opt_set(c->priv_data, "preset", "medium", 0);

       if(avcodec_open2(c, codec, NULL) &lt; 0)
       {
           std::cout &lt;&lt; "Could not open codec." &lt;&lt; std::endl;
           std::cin.get();std::cin.get();exit(1);
       }
       video_outbuf = NULL;
       if(!(oc->oformat->flags &amp; AVFMT_RAWPICTURE))
       {
           video_outbuf_size = 200000;
           video_outbuf = (uint8_t*)(av_malloc(video_outbuf_size));
       }
       picture = alloc_picture(c->pix_fmt, c->width, c->height);
       if(!picture)
       {
           std::cout &lt;&lt; "Could not allocate picture" &lt;&lt; std::endl;
           std::cin.get();exit(1);
       }
       tmp_picture = NULL;
       if(c->pix_fmt != AV_PIX_FMT_YUV420P)
       {
           tmp_picture = alloc_picture(AV_PIX_FMT_YUV420P, WIDTH, HEIGHT);
           if(!tmp_picture)
           {
               std::cout &lt;&lt; " Could not allocate temporary picture" &lt;&lt; std::endl;
               std::cin.get();exit(1);
           }
       }
    }


    static AVStream* addVideoStream(AVFormatContext *context, enum AVCodecID codecID)
    {
       AVCodecContext *codec;
       AVStream *stream;
       stream = avformat_new_stream(context, NULL);
       if(!stream)
       {
           std::cout &lt;&lt; "Could not alloc stream." &lt;&lt; std::endl;
           std::cin.get();exit(1);
       }

       codec = stream->codec;
       codec->codec_id = codecID;
       codec->codec_type = AVMEDIA_TYPE_VIDEO;

       // sample rate
       codec->bit_rate = BIT_RATE;
       // resolution must be a multiple of two
       codec->width = WIDTH;
       codec->height = HEIGHT;
       codec->time_base.den = FRAME_RATE; // stream fps
       codec->time_base.num = 1;
       codec->gop_size = 12; // intra frame every twelve frames at most
       codec->pix_fmt = PIXEL_FORMAT;
       if(codec->codec_id == AV_CODEC_ID_MPEG2VIDEO)
           codec->max_b_frames = 2; // for testing, B frames

       if(codec->codec_id == AV_CODEC_ID_MPEG1VIDEO)
           codec->mb_decision = 2;

       if(context->oformat->flags &amp; AVFMT_GLOBALHEADER)
           codec->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;

       return stream;
    }

    static void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height)
    {
       int x, y, i;
       i = frame_index;

       /* Y */
       for(y=0;ydata[0][y * pict->linesize[0] + x] = x + y + i * 3;
           }
       }

       /* Cb and Cr */
       for(y=0;y<height></height>2;y++) {
           for(x=0;x<width></width>2;x++) {
               pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
               pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
           }
       }
    }

    static void write_video_frame(AVFormatContext *oc, AVStream *st)
    {
       int out_size, ret;
       AVCodecContext *c;
       static struct SwsContext *img_convert_ctx;
       c = st->codec;

       if(frame_count >= STREAM_NB_FRAMES)
       {

       }
       else
       {
           if(c->pix_fmt != AV_PIX_FMT_YUV420P)
           {
               if(img_convert_ctx = NULL)
               {
                   img_convert_ctx = sws_getContext(WIDTH, HEIGHT, AV_PIX_FMT_YUV420P, WIDTH, HEIGHT,
                                                   c->pix_fmt, sws_flags, NULL, NULL, NULL);
                   if(img_convert_ctx == NULL)
                   {
                       std::cout &lt;&lt; "Cannot initialize the conversion context" &lt;&lt; std::endl;
                       std::cin.get();exit(1);
                   }
               }
               fill_yuv_image(tmp_picture, frame_count, WIDTH, HEIGHT);
               sws_scale(img_convert_ctx, tmp_picture->data, tmp_picture->linesize, 0, HEIGHT,
                           picture->data, picture->linesize);
           }
           else
           {
               fill_yuv_image(picture, frame_count, WIDTH, HEIGHT);
           }
       }

       if (oc->oformat->flags &amp; AVFMT_RAWPICTURE)
       {
           /* raw video case. The API will change slightly in the near
              futur for that */
           AVPacket pkt;
           av_init_packet(&amp;pkt);

           pkt.flags |= AV_PKT_FLAG_KEY;
           pkt.stream_index= st->index;
           pkt.data= (uint8_t *)picture;
           pkt.size= sizeof(AVPicture);

           ret = av_interleaved_write_frame(oc, &amp;pkt);
       }
       else
       {
           /* encode the image */
           out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture);
           /* if zero size, it means the image was buffered */
           if (out_size > 0)
           {
               AVPacket pkt;
               av_init_packet(&amp;pkt);

               if (c->coded_frame->pts != AV_NOPTS_VALUE)
                   pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base);
               if(c->coded_frame->key_frame)
                   pkt.flags |= AV_PKT_FLAG_KEY;
               pkt.stream_index= st->index;
               pkt.data= video_outbuf;
               pkt.size= out_size;
               /* write the compressed frame in the media file */
               ret = av_interleaved_write_frame(oc, &amp;pkt);
           } else {
               ret = 0;
           }
       }
       if (ret != 0) {
           std::cout &lt;&lt; "Error while writing video frames" &lt;&lt; std::endl;
           std::cin.get();exit(1);
       }
       frame_count++;
    }

    int main ( int argc, char *argv[] )
    {
       const char* filename = "test.h264";
       AVOutputFormat *outputFormat;
       AVFormatContext *context;
       AVCodecContext *codec;
       AVStream *videoStream;
       double videoPTS;

       // init libavcodec, register all codecs and formats
       av_register_all();
       // auto detect the output format from the name
       outputFormat = av_guess_format(NULL, filename, NULL);
       if(!outputFormat)
       {
           std::cout &lt;&lt; "Cannot guess output format! Using mpeg!" &lt;&lt; std::endl;
           std::cin.get();
           outputFormat = av_guess_format(NULL, "h263" , NULL);
       }
       if(!outputFormat)
       {
           std::cout &lt;&lt; "Could not find suitable output format." &lt;&lt; std::endl;
           std::cin.get();exit(1);
       }

       context = avformat_alloc_context();
       if(!context)
       {
           std::cout &lt;&lt; "Cannot allocate avformat memory." &lt;&lt; std::endl;
           std::cin.get();exit(1);
       }
       context->oformat = outputFormat;
       sprintf_s(context->filename, sizeof(context->filename), "%s", filename);
       std::cout &lt;&lt; "Is '" &lt;&lt; context->filename &lt;&lt; "' = '" &lt;&lt; filename &lt;&lt; "'" &lt;&lt; std::endl;


       videoStream = NULL;
       outputFormat->audio_codec = AV_CODEC_ID_NONE;
       videoStream = addVideoStream(context, outputFormat->video_codec);

       /* still needed?
       if(av_set_parameters(context, NULL) &lt; 0)
       {
           std::cout &lt;&lt; "Invalid output format parameters." &lt;&lt; std::endl;
           exit(0);
       }*/

       av_dump_format(context, 0, filename, 1);

       if(videoStream)
           openVideo(context, videoStream);

       if(!outputFormat->flags &amp; AVFMT_NOFILE)
       {
           if(avio_open(&amp;context->pb, filename, AVIO_FLAG_READ_WRITE) &lt; 0)
           {
               std::cout &lt;&lt; "Could not open " &lt;&lt; filename &lt;&lt; std::endl;
               std::cin.get();exit(1);
           }
       }

       avformat_write_header(context, 0);

       while(true)
       {
           if(videoStream)
               videoPTS = (double) videoStream->pts.val * videoStream->time_base.num / videoStream->time_base.den;
           else
               videoPTS = 0.;

           if((!videoStream || videoPTS >= STREAM_DURATION))
           {
               break;
           }
           write_video_frame(context, videoStream);
       }
       av_write_trailer(context);
       if(videoStream)
           closeVideo(context, videoStream);
       for(int i = 0; i &lt; context->nb_streams; i++)
       {
           av_freep(&amp;context->streams[i]->codec);
           av_freep(&amp;context->streams[i]);
       }

       if(!(outputFormat->flags &amp; AVFMT_NOFILE))
       {
           avio_close(context->pb);
       }
       av_free(context);
       std::cin.get();
       return 0;
    }
    </string></iostream>

    Compile :

    g++ -I ./FFmpeg/ video.cpp -L fflibs -lavcodec -lavformat

    The code comes with two errors :

    video.cpp:249:84: error: ‘avcodec_encode_video’ was not declared in this scope
            out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture);
                                                                                       ^


    video.cpp: In function ‘int main(int, char**)’:
    video.cpp:342:46: error: ‘AVStream {aka struct AVStream}’ has no member named ‘pts’
                videoPTS = (double) videoStream->pts.val * videoStream->time_base.num / videoStream->time_base.den;
                                                 ^

    and a huge number of warnings for deprecation.

    video.cpp: In function ‘void closeVideo(AVFormatContext*, AVStream*)’:
    video.cpp:60:23: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
        avcodec_close(st->codec);
                          ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp:60:23: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
        avcodec_close(st->codec);
                          ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp:60:23: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
        avcodec_close(st->codec);
                          ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp: In function ‘AVFrame* alloc_picture(AVPixelFormat, int, int)’:
    video.cpp:80:12: warning: ‘int avpicture_get_size(AVPixelFormat, int, int)’ is deprecated [-Wdeprecated-declarations]
        size = avpicture_get_size(pix_fmt, width, height);
               ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:5228:5: note: declared here
    int avpicture_get_size(enum AVPixelFormat pix_fmt, int width, int height);
        ^
    video.cpp:80:12: warning: ‘int avpicture_get_size(AVPixelFormat, int, int)’ is deprecated [-Wdeprecated-declarations]
        size = avpicture_get_size(pix_fmt, width, height);
               ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:5228:5: note: declared here
    int avpicture_get_size(enum AVPixelFormat pix_fmt, int width, int height);
        ^
    video.cpp:80:53: warning: ‘int avpicture_get_size(AVPixelFormat, int, int)’ is deprecated [-Wdeprecated-declarations]
        size = avpicture_get_size(pix_fmt, width, height);
                                                        ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:5228:5: note: declared here
    int avpicture_get_size(enum AVPixelFormat pix_fmt, int width, int height);
        ^
    video.cpp:87:5: warning: ‘int avpicture_fill(AVPicture*, const uint8_t*, AVPixelFormat, int, int)’ is deprecated [-Wdeprecated-declarations]
        avpicture_fill((AVPicture *) picture, picture_buf, pix_fmt, WIDTH, HEIGHT);
        ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:5213:5: note: declared here
    int avpicture_fill(AVPicture *picture, const uint8_t *ptr,
        ^
    video.cpp:87:5: warning: ‘int avpicture_fill(AVPicture*, const uint8_t*, AVPixelFormat, int, int)’ is deprecated [-Wdeprecated-declarations]
        avpicture_fill((AVPicture *) picture, picture_buf, pix_fmt, WIDTH, HEIGHT);
        ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:5213:5: note: declared here
    int avpicture_fill(AVPicture *picture, const uint8_t *ptr,
        ^
    video.cpp:87:78: warning: ‘int avpicture_fill(AVPicture*, const uint8_t*, AVPixelFormat, int, int)’ is deprecated [-Wdeprecated-declarations]
        avpicture_fill((AVPicture *) picture, picture_buf, pix_fmt, WIDTH, HEIGHT);
                                                                                 ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:5213:5: note: declared here
    int avpicture_fill(AVPicture *picture, const uint8_t *ptr,
        ^
    video.cpp: In function ‘void openVideo(AVFormatContext*, AVStream*)’:
    video.cpp:96:13: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
        c = st->codec;
                ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp:96:13: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
        c = st->codec;
                ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp:96:13: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
        c = st->codec;
                ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp: In function ‘AVStream* addVideoStream(AVFormatContext*, AVCodecID)’:
    video.cpp:151:21: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
        codec = stream->codec;
                        ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp:151:21: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
        codec = stream->codec;
                        ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp:151:21: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
        codec = stream->codec;
                        ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp: In function ‘void write_video_frame(AVFormatContext*, AVStream*)’:
    video.cpp:202:13: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
        c = st->codec;
                ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp:202:13: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
        c = st->codec;
                ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp:202:13: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
        c = st->codec;
                ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp:256:20: warning: ‘AVCodecContext::coded_frame’ is deprecated [-Wdeprecated-declarations]
                if (c->coded_frame->pts != AV_NOPTS_VALUE)
                       ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:2723:35: note: declared here
        attribute_deprecated AVFrame *coded_frame;
                                      ^
    video.cpp:256:20: warning: ‘AVCodecContext::coded_frame’ is deprecated [-Wdeprecated-declarations]
                if (c->coded_frame->pts != AV_NOPTS_VALUE)
                       ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:2723:35: note: declared here
        attribute_deprecated AVFrame *coded_frame;
                                      ^
    video.cpp:256:20: warning: ‘AVCodecContext::coded_frame’ is deprecated [-Wdeprecated-declarations]
                if (c->coded_frame->pts != AV_NOPTS_VALUE)
                       ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:2723:35: note: declared here
        attribute_deprecated AVFrame *coded_frame;
                                      ^
    video.cpp:257:42: warning: ‘AVCodecContext::coded_frame’ is deprecated [-Wdeprecated-declarations]
                    pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base);
                                             ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:2723:35: note: declared here
        attribute_deprecated AVFrame *coded_frame;
                                      ^
    video.cpp:257:42: warning: ‘AVCodecContext::coded_frame’ is deprecated [-Wdeprecated-declarations]
                    pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base);
                                             ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:2723:35: note: declared here
        attribute_deprecated AVFrame *coded_frame;
                                      ^
    video.cpp:257:42: warning: ‘AVCodecContext::coded_frame’ is deprecated [-Wdeprecated-declarations]
                    pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base);
                                             ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:2723:35: note: declared here
        attribute_deprecated AVFrame *coded_frame;
                                      ^
    video.cpp:258:19: warning: ‘AVCodecContext::coded_frame’ is deprecated [-Wdeprecated-declarations]
                if(c->coded_frame->key_frame)
                      ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:2723:35: note: declared here
        attribute_deprecated AVFrame *coded_frame;
                                      ^
    video.cpp:258:19: warning: ‘AVCodecContext::coded_frame’ is deprecated [-Wdeprecated-declarations]
                if(c->coded_frame->key_frame)
                      ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:2723:35: note: declared here
        attribute_deprecated AVFrame *coded_frame;
                                      ^
    video.cpp:258:19: warning: ‘AVCodecContext::coded_frame’ is deprecated [-Wdeprecated-declarations]
                if(c->coded_frame->key_frame)
                      ^
    In file included from video.cpp:8:0:
    ./FFmpeg/libavcodec/avcodec.h:2723:35: note: declared here
        attribute_deprecated AVFrame *coded_frame;
                                      ^
    video.cpp:357:40: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
            av_freep(&amp;context->streams[i]->codec);
                                           ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp:357:40: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
            av_freep(&amp;context->streams[i]->codec);
                                           ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp:357:40: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]
            av_freep(&amp;context->streams[i]->codec);
                                           ^
    In file included from video.cpp:9:0:
    ./FFmpeg/libavformat/avformat.h:876:21: note: declared here
        AVCodecContext *codec;
                        ^
    video.cpp:337:38: warning: ignoring return value of ‘int avformat_write_header(AVFormatContext*, AVDictionary**)’, declared with attribute warn_unused_result [-Wunused-result]
        avformat_write_header(context, 0);
                                         ^

    I have also defined a few macros to redefine those who have been omited. In a modern ffmpeg API, they must be replaced.

    Could someone please help me solving errors and deprecation warnings to comply with recent ffmpeg API ?

  • What is data anonymization in web analytics ?

    11 février 2020, par Joselyn Khor — Analytics Tips, Privacy

    Collecting information via web analytics platforms is needed to help a website grow and improve. When doing so, it’s best to strike a balance between getting valuable insights, and keeping the trust of your users by protecting their privacy.

    This means not collecting or processing any personally identifiable information (PII). But what if your organisation requires you to collect PII ?

    That’s where data anonymization comes in.

    What is data anonymization ?

    Data anonymization makes identifiable information unidentifiable. This is done through data processing techniques which remove or modify PII data. So data becomes anonymous and can’t be linked to any individual.

    In the context of web analytics, data anonymization is handy because you can collect useful data while protecting the privacy of website visitors.

    Why is data anonymization important ?

    Through modern threats of identity theft, credit card fraud and the like, data anonymization is a way to protect the identity and privacy of individuals. As well as protect private and sensitive information of organisations. 

    Data anonymization lets you follow the many laws around the world which protect user privacy. These laws provide safeguards around collecting personal data or personally identifiable information (PII), so data anonymization is a good solution to ensure you’re not processing such sensitive information.

    In some cases, implementing data anonymization techniques means you can avoid having to show your users a consent screen. Which means you may not need to ask for consent in order to track data. This is a bonus as consent screens can annoy and stop people from engaging with your site.

    GDPR and data anonymization

    Matomo Analytics GDPR Google Analytics

    The GDPR is a law in the EU that limits the collection and processing of personal data. The aim is to give people more control over their online personal information. Which is why website owners need to follow certain rules to become GDPR compliant and protect user privacy. According to the GDPR, you can be fined up to 4% of your yearly revenue for data breaches or non-compliance. 

    In the case of web analytics, tools can be easily made compliant by following a number of steps

    This is why anonymizing data is a big deal.

    Anonymized data isn’t personal data according to the GDPR : 

    “The principles of data protection should therefore not apply to anonymous information, namely information which does not relate to an identified or identifiable natural person or to personal data rendered anonymous in such a manner that the data subject is not or no longer identifiable.”

    This means, you still get the best of both worlds. By anonymizing data, you’re still able to collect useful information like visitor behavioural data.

    US privacy laws and data anonymization

    In the US, there isn’t one single law that governs the protection of personal data, called personally identifiable information (PII). There are hundreds of federal and state laws that protect the personal data of US residents. As well as, industry-specific statutes related to data privacy, like the California Consumer Privacy Act (CCPA) and the Health Insurance Portability and Accountability Act (HIPAA).

    Website owners in the US need to know exactly what laws govern their area of business in order to follow them.

    A general guideline is to protect user privacy regardless of whether you are or aren’t allowed to collect PII. This means anonymizing identifiable information so your website users aren’t put at risk.

    Data anonymization techniques in Matomo Analytics

    If you carry these out, you won’t need to ask your website visitors for tracking consent since anonymized data is no longer considered personal data under the GDPR.

    The techniques listed above make it easy for you when using a tool like Matomo, as they are automatically anonymized.

    Tools like Google Analytics on the other hand don’t provide some of the privacy options and leave it up to you to take on the burden of implementation without providing steps.

    Data anonymization tools

    If you’re a website owner who wants to grow your business or learn more about your website visitors, privacy-friendly tools like Matomo Analytics are a great option. By following the easy steps to be GDPR compliant, you can anonymize all data that could put your visitors at risk.

  • Neutral net or neutered

    4 juin 2013, par Mans — Law and liberty

    In recent weeks, a number of high-profile events, in the UK and elsewhere, have been quickly seized upon to promote a variety of schemes for monitoring or filtering Internet access. These proposals, despite their good intentions of protecting children or fighting terrorism, pose a serious threat to fundamental liberties. Although at a glance the ideas may seem like a reasonable price to pay for the prevention of some truly hideous crimes, there is more than first meets the eye. Internet regulation in any form whatsoever is the thin end of a wedge at whose other end we find severely restricted freedom of expression of the kind usually associated with oppressive dictatorships. Where the Internet was once a novelty, it now forms an integrated part of modern society ; regulating the Internet means regulating our lives.

    Terrorism

    Following the brutal murder of British soldier Lee Rigby in Woolwich, attempts were made in the UK to revive the controversial Communications Data Bill, also dubbed the snooper’s charter. The bill would give police and security services unfettered access to details (excluding content) of all digital communication in the UK without needing so much as a warrant.

    The powers afforded by the snooper’s charter would, the argument goes, enable police to prevent crimes such as the one witnessed in Woolwich. True or not, the proposal would, if implemented, also bring about infrastructure for snooping on anyone at any time for any purpose. Once available, the temptation may become strong to extend, little by little, the legal use of these abilities to cover ever more everyday activities, all in the name of crime prevention, of course.

    In the emotional aftermath of a gruesome act, anything with the promise of preventing it happening again may seem like a good idea. At times like these it is important, more than ever, to remain rational and carefully consider all the potential consequences of legislation, not only the intended ones.

    Hate speech

    Hand in hand with terrorism goes hate speech, preachings designed to inspire violence against people of some singled-out nation, race, or other group. Naturally, hate speech is often to be found on the Internet, where it can reach large audiences while the author remains relatively protected. Naturally, we would prefer for it not to exist.

    To fulfil the utopian desire of a clean Internet, some advocate mandatory filtering by Internet service providers and search engines to remove this unwanted content. Exactly how such censoring might be implemented is however rarely dwelt upon, much less the consequences inadvertent blocking of innocent material might have.

    Pornography

    Another common target of calls for filtering is pornography. While few object to the blocking of child pornography, at least in principle, the debate runs hotter when it comes to the legal variety. Pornography, it is claimed, promotes violence towards women and is immoral or generally offensive. As such it ought to be blocked in the name of the greater good.

    The conviction last week of paedophile Mark Bridger for the abduction and murder of five-year-old April Jones renewed the debate about filtering of pornography in the UK ; his laptop was found to contain child pornography. John Carr of the UK government’s Council on Child Internet Safety went so far as suggesting a default blocking of all pornography, access being granted to an Internet user only once he or she had registered with some unspecified entity. Registering people wishing only to access perfectly legal material is not something we do in a democracy.

    The reality is that Google and other major search engines already remove illegal images from search results and report them to the appropriate authorities. In the UK, the Internet Watch Foundation, a non-government organisation, maintains a blacklist of what it deems ‘potentially criminal’ content, and many Internet service providers block access based on this list.

    While well-intentioned, the IWF and its blacklist should raise some concerns. Firstly, a vigilante organisation operating in secret and with no government oversight acting as the nation’s morality police has serious implications for freedom of speech. Secondly, the blocks imposed are sometimes more far-reaching than intended. In one incident, an attempt to block the cover image of the Scorpions album Virgin Killer hosted by Wikipedia (in itself a dubious decision) rendered the entire related article inaccessible as well as interfered with editing.

    Net neutrality

    Content filtering, or more precisely the lack thereof, is central to the concept of net neutrality. Usually discussed in the context of Internet service providers, this is the principle that the user should have equal, unfiltered access to all content. As a consequence, ISPs should not be held responsible for the content they deliver. Compare this to how the postal system works.

    The current debate shows that the principle of net neutrality is important not only at the ISP level, but should also include providers of essential services on the Internet. This means search engines should not be responsible for or be required to filter results, email hosts should not be required to scan users’ messages, and so on. No mandatory censoring can be effective without infringing the essential liberties of freedom of speech and press.

    Social networks operate in a less well-defined space. They are clearly not part of the essential Internet infrastructure, and they require that users sign up and agree to their terms and conditions. Because of this, they can include restrictions that would be unacceptable for the Internet as a whole. At the same time, social networks are growing in importance as means of communication between people, and as such they have a moral obligation to act fairly and apply their rules in a transparent manner.

    Facebook was recently under fire, accused of not taking sufficient measures to curb ‘hate speech,’ particularly against women. Eventually they pledged to review their policies and methods, and reducing the proliferation of such content will surely make the web a better place. Nevertheless, one must ask how Facebook (or another social network) might react to similar pressure from, say, a religious group demanding removal of ‘blasphemous’ content. What about demands from a foreign government ? Only yesterday, the Turkish prime minister Erdogan branded Twitter ‘a plague’ in a TV interview.

    Rather than impose upon Internet companies the burden of law enforcement, we should provide them the latitude to set their own policies as well as the legal confidence to stand firm in the face of unreasonable demands. The usual market forces will promote those acting responsibly.

    Further reading