On Fri, Jul 28, 2017 at 14:01:37 +0800, Jun Zhao wrote: It doesn't really matter much functionally, but I consider it good style to report errors properly, especially in an example which will be used by others:
> + fin = fopen(input_file, "r"); > + fout = fopen(output_file, "w+b"); > + if (!fin || !fout) { > + fprintf(stderr, "Fail to open input or output file.\n"); Here, one would evaluate errno on each fopen(), e.g. with perror() or whatever ffmpeg's equivalent is. > + ret = av_hwdevice_ctx_create(&hw_device_ctx, AV_HWDEVICE_TYPE_VAAPI, > + NULL, NULL, 0); > + if (ret < 0) { > + fprintf(stderr, "Failed to create a VAAPI device.\n"); The AVERROR return code should be reported to the user, e.g. by the use of av_err2str(ret) (see other examples). > + if (!(codec = avcodec_find_encoder_by_name(enc_name))) { > + fprintf(stderr, "Could not find encoder.\n"); > + if ((ret = init_filter(filter_ctx, args, hw_device_ctx)) < 0) { > + fprintf(stderr, "Failed to initialize the filtering context.\n"); > + if ((ret = avcodec_open2(avctx, codec, NULL)) < 0) > + fprintf(stderr, "Cannot open video encoder codec.\n"); > + ret = av_buffersrc_add_frame_flags(filter_ctx->buffersrc_ctx, > + sw_frame, 0); > + if (ret < 0) { > + fprintf(stderr, "Error while feeding the filtergraph.\n"); Probably the same for all the above. Cheers, Moritz _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel