vhook/null.c

   1 /*
   2  * Null Video Hook
   3  * Copyright (c) 2002 Philip Gladstone
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21 #include <stdio.h>
  22
  23 #include "libavformat/framehook.h"
  24 #include "libswscale/swscale.h"
  25
  26 static int sws_flags = SWS_BICUBIC;
  27
  28 typedef struct {
  29     int dummy;
  30
  31     // This vhook first converts frame to RGB ...
  32     struct SwsContext *toRGB_convert_ctx;
  33
  34     // ... and later converts back frame from RGB to initial format
  35     struct SwsContext *fromRGB_convert_ctx;
  36
  37 } ContextInfo;
  38
  39 void Release(void *ctx)
  40 {
  41     ContextInfo *ci;
  42     ci = (ContextInfo *) ctx;
  43
  44     if (ctx) {
  45         sws_freeContext(ci->toRGB_convert_ctx);
  46         sws_freeContext(ci->fromRGB_convert_ctx);
  47         av_free(ctx);
  48     }
  49 }
  50
  51 int Configure(void **ctxp, int argc, char *argv[])
  52 {
  53     fprintf(stderr, "Called with argc=%d\n", argc);
  54
  55     *ctxp = av_mallocz(sizeof(ContextInfo));
  56     return 0;
  57 }
  58
  59 void Process(void *ctx, AVPicture *picture, enum PixelFormat pix_fmt, int width, int height, int64_t pts)
  60 {
  61     ContextInfo *ci = (ContextInfo *) ctx;
  62     char *buf = 0;
  63     AVPicture picture1;
  64     AVPicture *pict = picture;
  65
  66     (void) ci;
  67
  68     if (pix_fmt != PIX_FMT_RGB24) {
  69         int size;
  70
  71         size = avpicture_get_size(PIX_FMT_RGB24, width, height);
  72         buf = av_malloc(size);
  73
  74         avpicture_fill(&picture1, buf, PIX_FMT_RGB24, width, height);
  75
  76         // if we already got a SWS context, let's realloc if is not re-useable
  77         ci->toRGB_convert_ctx = sws_getCachedContext(ci->toRGB_convert_ctx,
  78                                     width, height, pix_fmt,
  79                                     width, height, PIX_FMT_RGB24,
  80                                     sws_flags, NULL, NULL, NULL);
  81         if (ci->toRGB_convert_ctx == NULL) {
  82             av_log(NULL, AV_LOG_ERROR,
  83                    "Cannot initialize the toRGB conversion context\n");
  84             return;
  85         }
  86 // img_convert parameters are          2 first destination, then 4 source
  87 // sws_scale   parameters are context, 4 first source,      then 2 destination
  88         sws_scale(ci->toRGB_convert_ctx,
  89             picture->data, picture->linesize, 0, height,
  90             picture1.data, picture1.linesize);
  91
  92         pict = &picture1;
  93     }
  94
  95     /* Insert filter code here */
  96
  97     if (pix_fmt != PIX_FMT_RGB24) {
  98         ci->fromRGB_convert_ctx = sws_getCachedContext(ci->fromRGB_convert_ctx,
  99                                         width, height, PIX_FMT_RGB24,
 100                                         width, height, pix_fmt,
 101                                         sws_flags, NULL, NULL, NULL);
 102         if (ci->fromRGB_convert_ctx == NULL) {
 103             av_log(NULL, AV_LOG_ERROR,
 104                    "Cannot initialize the fromRGB conversion context\n");
 105             return;
 106         }
 107 // img_convert parameters are          2 first destination, then 4 source
 108 // sws_scale   parameters are context, 4 first source,      then 2 destination
 109         sws_scale(ci->fromRGB_convert_ctx,
 110             picture1.data, picture1.linesize, 0, height,
 111             picture->data, picture->linesize);
 112     }
 113
 114     av_free(buf);
 115 }
 116