FFmpeg: libavfilter/vf_alphamerge.c Source File

FFmpeg
vf_alphamerge.c
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1 /*
2  * Copyright (c) 2012 Steven Robertson
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 /**
22  * @file
23  * copy an alpha component from another video's luma
24  */
25 
26 #include <string.h>
27 
28 #include "libavutil/pixfmt.h"
29 #include "avfilter.h"
30 #include "bufferqueue.h"
31 #include "drawutils.h"
32 #include "formats.h"
33 #include "internal.h"
34 #include "video.h"
35 
36  enum { Y, U, V, A };
37 
38  typedef struct {
39   int frame_requested;
40   int is_packed_rgb;
41   uint8_t rgba_map[4];
42   struct FFBufQueue queue_main;
43   struct FFBufQueue queue_alpha;
44 } AlphaMergeContext;
45 
46  static av_cold void uninit(AVFilterContext *ctx)
47 {
48  AlphaMergeContext *merge = ctx->priv;
49  ff_bufqueue_discard_all(&merge->queue_main);
50  ff_bufqueue_discard_all(&merge->queue_alpha);
51 }
52 
53  static int query_formats(AVFilterContext *ctx)
54 {
55  static const enum AVPixelFormat main_fmts[] = {
56  AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
57  AV_PIX_FMT_RGBA, AV_PIX_FMT_BGRA, AV_PIX_FMT_ARGB, AV_PIX_FMT_ABGR,
58  AV_PIX_FMT_NONE
59  };
60  static const enum AVPixelFormat alpha_fmts[] = { AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE };
61  AVFilterFormats *main_formats = ff_make_format_list(main_fmts);
62  AVFilterFormats *alpha_formats = ff_make_format_list(alpha_fmts);
63  ff_formats_ref(main_formats, &ctx->inputs[0]->out_formats);
64  ff_formats_ref(alpha_formats, &ctx->inputs[1]->out_formats);
65  ff_formats_ref(main_formats, &ctx->outputs[0]->in_formats);
66  return 0;
67 }
68 
69  static int config_input_main(AVFilterLink *inlink)
70 {
71  AlphaMergeContext *merge = inlink->dst->priv;
72  merge->is_packed_rgb =
73  ff_fill_rgba_map(merge->rgba_map, inlink->format) >= 0;
74  return 0;
75 }
76 
77  static int config_output(AVFilterLink *outlink)
78 {
79  AVFilterContext *ctx = outlink->src;
80  AVFilterLink *mainlink = ctx->inputs[0];
81  AVFilterLink *alphalink = ctx->inputs[1];
82  if (mainlink->w != alphalink->w || mainlink->h != alphalink->h) {
83  av_log(ctx, AV_LOG_ERROR,
84  "Input frame sizes do not match (%dx%d vs %dx%d).\n",
85  mainlink->w, mainlink->h,
86  alphalink->w, alphalink->h);
87  return AVERROR(EINVAL);
88  }
89 
90  outlink->w = mainlink->w;
91  outlink->h = mainlink->h;
92  outlink->time_base = mainlink->time_base;
93  outlink->sample_aspect_ratio = mainlink->sample_aspect_ratio;
94  outlink->frame_rate = mainlink->frame_rate;
95  return 0;
96 }
97 
98  static void draw_frame(AVFilterContext *ctx,
99  AVFrame *main_buf,
100  AVFrame *alpha_buf)
101 {
102  AlphaMergeContext *merge = ctx->priv;
103  int h = main_buf->height;
104 
105  if (merge->is_packed_rgb) {
106  int x, y;
107  uint8_t *pin, *pout;
108  for (y = 0; y < h; y++) {
109  pin = alpha_buf->data[0] + y * alpha_buf->linesize[0];
110  pout = main_buf->data[0] + y * main_buf->linesize[0] + merge->rgba_map[A];
111  for (x = 0; x < main_buf->width; x++) {
112  *pout = *pin;
113  pin += 1;
114  pout += 4;
115  }
116  }
117  } else {
118  int y;
119  const int main_linesize = main_buf->linesize[A];
120  const int alpha_linesize = alpha_buf->linesize[Y];
121  for (y = 0; y < h && y < alpha_buf->height; y++) {
122  memcpy(main_buf->data[A] + y * main_linesize,
123  alpha_buf->data[Y] + y * alpha_linesize,
124  FFMIN(main_linesize, alpha_linesize));
125  }
126  }
127 }
128 
129  static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
130 {
131  AVFilterContext *ctx = inlink->dst;
132  AlphaMergeContext *merge = ctx->priv;
133 
134  int ret = 0;
135  int is_alpha = (inlink == ctx->inputs[1]);
136  struct FFBufQueue *queue =
137  (is_alpha ? &merge->queue_alpha : &merge->queue_main);
138  ff_bufqueue_add(ctx, queue, buf);
139 
140  do {
141  AVFrame *main_buf, *alpha_buf;
142 
143  if (!ff_bufqueue_peek(&merge->queue_main, 0) ||
144  !ff_bufqueue_peek(&merge->queue_alpha, 0)) break;
145 
146  main_buf = ff_bufqueue_get(&merge->queue_main);
147  alpha_buf = ff_bufqueue_get(&merge->queue_alpha);
148 
149  merge->frame_requested = 0;
150  draw_frame(ctx, main_buf, alpha_buf);
151  ret = ff_filter_frame(ctx->outputs[0], main_buf);
152  av_frame_free(&alpha_buf);
153  } while (ret >= 0);
154  return ret;
155 }
156 
157  static int request_frame(AVFilterLink *outlink)
158 {
159  AVFilterContext *ctx = outlink->src;
160  AlphaMergeContext *merge = ctx->priv;
161  int in, ret;
162 
163  merge->frame_requested = 1;
164  while (merge->frame_requested) {
165  in = ff_bufqueue_peek(&merge->queue_main, 0) ? 1 : 0;
166  ret = ff_request_frame(ctx->inputs[in]);
167  if (ret < 0)
168  return ret;
169  }
170  return 0;
171 }
172 
173  static const AVFilterPad alphamerge_inputs[] = {
174  {
175  .name = "main",
176  .type = AVMEDIA_TYPE_VIDEO,
177  .config_props = config_input_main,
178  .filter_frame = filter_frame,
179  .needs_writable = 1,
180  },{
181  .name = "alpha",
182  .type = AVMEDIA_TYPE_VIDEO,
183  .filter_frame = filter_frame,
184  },
185  { NULL }
186 };
187 
188  static const AVFilterPad alphamerge_outputs[] = {
189  {
190  .name = "default",
191  .type = AVMEDIA_TYPE_VIDEO,
192  .config_props = config_output,
193  .request_frame = request_frame,
194  },
195  { NULL }
196 };
197 
198  AVFilter ff_vf_alphamerge = {
199  .name = "alphamerge",
200  .description = NULL_IF_CONFIG_SMALL("Copy the luma value of the second "
201  "input into the alpha channel of the first input."),
202  .uninit = uninit,
203  .priv_size = sizeof(AlphaMergeContext),
204  .query_formats = query_formats,
205  .inputs = alphamerge_inputs,
206  .outputs = alphamerge_outputs,
207 };
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