libavformat/framehook.c

   1 /*
   2  * Video processing hooks
   3  * Copyright (c) 2000, 2001 Fabrice Bellard
   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 <errno.h>
  22 #include "config.h"
  23 #include "avformat.h"
  24 #include "framehook.h"
  25
  26 #if HAVE_DLFCN_H
  27 #include <dlfcn.h>
  28 #endif
  29
  30
  31 typedef struct FrameHookEntry {
  32     struct FrameHookEntry *next;
  33     FrameHookConfigureFn Configure;
  34     FrameHookProcessFn Process;
  35     FrameHookReleaseFn Release;
  36     void *ctx;
  37 } FrameHookEntry;
  38
  39 static FrameHookEntry *first_hook;
  40
  41 /* Returns 0 on OK */
  42 int frame_hook_add(int argc, char *argv[])
  43 {
  44     void *loaded;
  45     FrameHookEntry *fhe, **fhep;
  46
  47     if (argc < 1) {
  48         return ENOENT;
  49     }
  50
  51     loaded = dlopen(argv[0], RTLD_NOW);
  52     if (!loaded) {
  53         av_log(NULL, AV_LOG_ERROR, "%s\n", dlerror());
  54         return -1;
  55     }
  56
  57     fhe = av_mallocz(sizeof(*fhe));
  58     if (!fhe) {
  59         return AVERROR(ENOMEM);
  60     }
  61
  62     fhe->Configure = dlsym(loaded, "Configure");
  63     fhe->Process = dlsym(loaded, "Process");
  64     fhe->Release = dlsym(loaded, "Release");    /* Optional */
  65
  66     if (!fhe->Process) {
  67         av_log(NULL, AV_LOG_ERROR, "Failed to find Process entrypoint in %s\n", argv[0]);
  68         return AVERROR(ENOENT);
  69     }
  70
  71     if (!fhe->Configure && argc > 1) {
  72         av_log(NULL, AV_LOG_ERROR, "Failed to find Configure entrypoint in %s\n", argv[0]);
  73         return AVERROR(ENOENT);
  74     }
  75
  76     if (argc > 1 || fhe->Configure) {
  77         if (fhe->Configure(&fhe->ctx, argc, argv)) {
  78             av_log(NULL, AV_LOG_ERROR, "Failed to Configure %s\n", argv[0]);
  79             return AVERROR(EINVAL);
  80         }
  81     }
  82
  83     for (fhep = &first_hook; *fhep; fhep = &((*fhep)->next)) {
  84     }
  85
  86     *fhep = fhe;
  87
  88     return 0;
  89 }
  90
  91 void frame_hook_process(AVPicture *pict, enum PixelFormat pix_fmt, int width, int height, int64_t pts)
  92 {
  93     if (first_hook) {
  94         FrameHookEntry *fhe;
  95
  96         for (fhe = first_hook; fhe; fhe = fhe->next) {
  97             fhe->Process(fhe->ctx, pict, pix_fmt, width, height, pts);
  98         }
  99     }
 100 }
 101
 102 void frame_hook_release(void)
 103 {
 104     FrameHookEntry *fhe;
 105     FrameHookEntry *fhenext;
 106
 107     for (fhe = first_hook; fhe; fhe = fhenext) {
 108         fhenext = fhe->next;
 109         if (fhe->Release)
 110             fhe->Release(fhe->ctx);
 111         av_free(fhe);
 112     }
 113
 114     first_hook = NULL;
 115 }