/* * Null Video Hook * Copyright (c) 2002 Philip Gladstone * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */#include <stdio.h>#include "libavformat/framehook.h"#include "libswscale/swscale.h"static int sws_flags = SWS_BICUBIC;typedef struct {    int dummy;    // This vhook first converts frame to RGB ...    struct SwsContext *toRGB_convert_ctx;    // ... and later converts back frame from RGB to initial format    struct SwsContext *fromRGB_convert_ctx;} ContextInfo;void Release(void *ctx){    ContextInfo *ci;    ci = (ContextInfo *) ctx;    if (ctx) {        sws_freeContext(ci->toRGB_convert_ctx);        sws_freeContext(ci->fromRGB_convert_ctx);        av_free(ctx);    }}int Configure(void **ctxp, int argc, char *argv[]){    fprintf(stderr, "Called with argc=%d\n", argc);    *ctxp = av_mallocz(sizeof(ContextInfo));    return 0;}void Process(void *ctx, AVPicture *picture, enum PixelFormat pix_fmt, int width, int height, int64_t pts){    ContextInfo *ci = (ContextInfo *) ctx;    char *buf = 0;    AVPicture picture1;    AVPicture *pict = picture;    (void) ci;    if (pix_fmt != PIX_FMT_RGB24) {        int size;        size = avpicture_get_size(PIX_FMT_RGB24, width, height);        buf = av_malloc(size);        avpicture_fill(&picture1, buf, PIX_FMT_RGB24, width, height);        // if we already got a SWS context, let's realloc if is not re-useable        ci->toRGB_convert_ctx = sws_getCachedContext(ci->toRGB_convert_ctx,                                    width, height, pix_fmt,                                    width, height, PIX_FMT_RGB24,                                    sws_flags, NULL, NULL, NULL);        if (ci->toRGB_convert_ctx == NULL) {            av_log(NULL, AV_LOG_ERROR,                   "Cannot initialize the toRGB conversion context\n");            return;        }// img_convert parameters are          2 first destination, then 4 source// sws_scale   parameters are context, 4 first source,      then 2 destination        sws_scale(ci->toRGB_convert_ctx,            picture->data, picture->linesize, 0, height,            picture1.data, picture1.linesize);        pict = &picture1;    }    /* Insert filter code here */    if (pix_fmt != PIX_FMT_RGB24) {        ci->fromRGB_convert_ctx = sws_getCachedContext(ci->fromRGB_convert_ctx,                                        width, height, PIX_FMT_RGB24,                                        width, height, pix_fmt,                                        sws_flags, NULL, NULL, NULL);        if (ci->fromRGB_convert_ctx == NULL) {            av_log(NULL, AV_LOG_ERROR,                   "Cannot initialize the fromRGB conversion context\n");            return;        }// img_convert parameters are          2 first destination, then 4 source// sws_scale   parameters are context, 4 first source,      then 2 destination        sws_scale(ci->fromRGB_convert_ctx,            picture1.data, picture1.linesize, 0, height,            picture->data, picture->linesize);    }    av_free(buf);}