Recherche avancée

Sur d’autres sites (8642)

• FFMpeg Drawtext black pixels behind the font

  21 janvier 2023, par sweetngx

  I burn the name of the movie with drawtext to my movies converted with FFMPeg, but I noticed that the black pixels around the font are disturbing, as seen in the picture. I don't know if this is a missing line of code or the nature of drawtext itself. Do you think there is a solution to make the movie name more legible ?

  


  

  


• ffmpeg - make pixels transparent depending on how black they are

  8 juillet 2022, par TheForgot3n1

  Fully black pixels should be fully transparent. Grey pixels should be semi-transparent. White pixels should not be transparent at all. Is this possible to achieve in ffmpeg ?

  


• Using ffmpeg and cuda to push rtmp stream error

  16 mars 2023, par sean lin

  i wrote a exercise program using ffmpeg example vaapi_transcode, and change encoder to h264_nvenc. but avformat_write_header return error and "0x55555555a080 "Invalid argument". My code is below

  


  encoder_ctx->hw_frames_ctx = av_buffer_ref(decoder_ctx->hw_frames_ctx);
            if (!encoder_ctx->hw_frames_ctx) {
                ret = AVERROR(ENOMEM);
                goto fail;
            }
            /* set AVCodecContext Parameters for encoder, here we keep them stay
             * the same as decoder.
             * xxx: now the sample can't handle resolution change case.
             */
            encoder_ctx->codec_id = ofmt_ctx->video_codec_id;
            encoder_ctx->width = decoder_ctx->width;
            encoder_ctx->height = decoder_ctx->height;
            encoder_ctx->pix_fmt = AV_PIX_FMT_CUDA;
            encoder_ctx->bit_rate_tolerance = 3 * 1024 * 1024;
            encoder_ctx->time_base = (AVRational){1, 25};
            encoder_ctx->bit_rate = (int64_t)(3 * 1024 * 1024);
            encoder_ctx->gop_size = 25;
            encoder_ctx->framerate = (AVRational){25, 1};
            encoder_ctx->max_b_frames = 0;  // 时间优先,不要b帧

            // 拉流录像正常
            // encoder_ctx->time_base = av_inv_q(decoder_ctx->framerate);
            // encoder_ctx->pix_fmt   = AV_PIX_FMT_CUDA;
            // encoder_ctx->width     = decoder_ctx->width;
            // encoder_ctx->height    = decoder_ctx->height;

            if ((ret = avcodec_open2(encoder_ctx, enc_codec, NULL)) < 0) {
                fprintf(stderr, "Failed to open encode codec. Error code: %s\n",
                        av_err2str1(ret));
                goto fail;
            }
 
            if (!(ost = avformat_new_stream(ofmt_ctx, enc_codec))) {
                fprintf(stderr, "Failed to allocate stream for output format.\n");
                ret = AVERROR(ENOMEM);
                goto fail;
            }
 
            ost->time_base = encoder_ctx->time_base;
            ret = avcodec_parameters_from_context(ost->codecpar, encoder_ctx);
            if (ret < 0) {
                fprintf(stderr, "Failed to copy the stream parameters. "
                        "Error code: %s\n", av_err2str1(ret));
                goto fail;
            }
 
            /* write the stream header */
            if ((ret = avformat_write_header(ofmt_ctx, NULL)) < 0) {
                fprintf(stderr, "Error while writing stream header. "
                        "Error code: %s\n", av_err2str1(ret));
                goto fail;
            }


  


  I need help to resolve this problem. please tell me the right code, tx.