libavfilter/f_perms.c

   1 /*
   2  * Copyright (c) 2013 Clément Bœsch
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include "config_components.h"
  22
  23 #include "libavutil/lfg.h"
  24 #include "libavutil/opt.h"
  25 #include "libavutil/random_seed.h"
  26 #include "audio.h"
  27 #include "filters.h"
  28 #include "video.h"
  29
  30 enum mode {
  31     MODE_NONE,
  32     MODE_RO,
  33     MODE_RW,
  34     MODE_TOGGLE,
  35     MODE_RANDOM,
  36     NB_MODES
  37 };
  38
  39 typedef struct PermsContext {
  40     const AVClass *class;
  41     AVLFG lfg;
  42     int64_t random_seed;
  43     int mode;
  44 } PermsContext;
  45
  46 #define OFFSET(x) offsetof(PermsContext, x)
  47 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_VIDEO_PARAM
  48 #define TFLAGS AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_RUNTIME_PARAM
  49
  50 static const AVOption options[] = {
  51     { "mode", "select permissions mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64 = MODE_NONE}, MODE_NONE, NB_MODES-1, TFLAGS, .unit = "mode" },
  52         { "none",   "do nothing",                       0, AV_OPT_TYPE_CONST, {.i64 = MODE_NONE},            0, 0, TFLAGS, .unit = "mode" },
  53         { "ro",     "set all output frames read-only",  0, AV_OPT_TYPE_CONST, {.i64 = MODE_RO},              0, 0, TFLAGS, .unit = "mode" },
  54         { "rw",     "set all output frames writable",   0, AV_OPT_TYPE_CONST, {.i64 = MODE_RW},              0, 0, TFLAGS, .unit = "mode" },
  55         { "toggle", "switch permissions",               0, AV_OPT_TYPE_CONST, {.i64 = MODE_TOGGLE},          0, 0, TFLAGS, .unit = "mode" },
  56         { "random", "set permissions randomly",         0, AV_OPT_TYPE_CONST, {.i64 = MODE_RANDOM},          0, 0, TFLAGS, .unit = "mode" },
  57     { "seed", "set the seed for the random mode", OFFSET(random_seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT32_MAX, FLAGS },
  58     { NULL }
  59 };
  60
  61 static av_cold int init(AVFilterContext *ctx)
  62 {
  63     PermsContext *s = ctx->priv;
  64     uint32_t seed;
  65
  66     if (s->random_seed == -1)
  67         s->random_seed = av_get_random_seed();
  68     seed = s->random_seed;
  69     av_log(ctx, AV_LOG_INFO, "random seed: 0x%08"PRIx32"\n", seed);
  70     av_lfg_init(&s->lfg, seed);
  71
  72     return 0;
  73 }
  74
  75 enum perm                        {  RO,   RW  };
  76 static const char * const perm_str[2] = { "RO", "RW" };
  77
  78 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
  79 {
  80     int ret;
  81     AVFilterContext *ctx = inlink->dst;
  82     PermsContext *s = ctx->priv;
  83     AVFrame *out = frame;
  84     enum perm in_perm = av_frame_is_writable(frame) ? RW : RO;
  85     enum perm out_perm;
  86
  87     switch (s->mode) {
  88     case MODE_TOGGLE:   out_perm = in_perm == RO ? RW : RO;                 break;
  89     case MODE_RANDOM:   out_perm = av_lfg_get(&s->lfg) & 1 ? RW : RO;       break;
  90     case MODE_RO:       out_perm = RO;                                      break;
  91     case MODE_RW:       out_perm = RW;                                      break;
  92     default:            out_perm = in_perm;                                 break;
  93     }
  94
  95     av_log(ctx, AV_LOG_VERBOSE, "%s -> %s%s\n",
  96            perm_str[in_perm], perm_str[out_perm],
  97            in_perm == out_perm ? " (no-op)" : "");
  98
  99     if (in_perm == RO && out_perm == RW) {
 100         if ((ret = ff_inlink_make_frame_writable(inlink, &frame)) < 0)
 101             return ret;
 102         out = frame;
 103     } else if (in_perm == RW && out_perm == RO) {
 104         out = av_frame_clone(frame);
 105         if (!out)
 106             return AVERROR(ENOMEM);
 107     }
 108
 109     ret = ff_filter_frame(ctx->outputs[0], out);
 110
 111     if (in_perm == RW && out_perm == RO)
 112         av_frame_free(&frame);
 113     return ret;
 114 }
 115
 116 AVFILTER_DEFINE_CLASS_EXT(perms, "(a)perms", options);
 117
 118 #if CONFIG_APERMS_FILTER
 119
 120 static const AVFilterPad aperms_inputs[] = {
 121     {
 122         .name         = "default",
 123         .type         = AVMEDIA_TYPE_AUDIO,
 124         .filter_frame = filter_frame,
 125     },
 126 };
 127
 128 const FFFilter ff_af_aperms = {
 129     .p.name      = "aperms",
 130     .p.description= NULL_IF_CONFIG_SMALL("Set permissions for the output audio frame."),
 131     .p.priv_class= &perms_class,
 132     .p.flags     = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC |
 133                    AVFILTER_FLAG_METADATA_ONLY,
 134     .init        = init,
 135     .priv_size   = sizeof(PermsContext),
 136     FILTER_INPUTS(aperms_inputs),
 137     FILTER_OUTPUTS(ff_audio_default_filterpad),
 138     .process_command = ff_filter_process_command,
 139 };
 140 #endif /* CONFIG_APERMS_FILTER */
 141
 142 #if CONFIG_PERMS_FILTER
 143
 144 static const AVFilterPad perms_inputs[] = {
 145     {
 146         .name         = "default",
 147         .type         = AVMEDIA_TYPE_VIDEO,
 148         .filter_frame = filter_frame,
 149     },
 150 };
 151
 152 const FFFilter ff_vf_perms = {
 153     .p.name        = "perms",
 154     .p.description = NULL_IF_CONFIG_SMALL("Set permissions for the output video frame."),
 155     .p.priv_class  = &perms_class,
 156     .p.flags       = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC |
 157                      AVFILTER_FLAG_METADATA_ONLY,
 158     .init        = init,
 159     .priv_size   = sizeof(PermsContext),
 160     FILTER_INPUTS(perms_inputs),
 161     FILTER_OUTPUTS(ff_video_default_filterpad),
 162     .process_command = ff_filter_process_command,
 163 };
 164 #endif /* CONFIG_PERMS_FILTER */