vsrc_buffer.c
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1 /*
2  * Copyright (c) 2008 Vitor Sessak
3  *
4  * This file is part of Libav.
5  *
6  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
26 #include "avfilter.h"
27 #include "buffersrc.h"
28 #include "vsrc_buffer.h"
29 #include "libavutil/imgutils.h"
30 
31 typedef struct {
33  int h, w;
38 
39 #define CHECK_PARAM_CHANGE(s, c, width, height, format)\
40  if (c->w != width || c->h != height || c->pix_fmt != format) {\
41  av_log(s, AV_LOG_ERROR, "Changing frame properties on the fly is not supported.\n");\
42  return AVERROR(EINVAL);\
43  }
44 
46  int64_t pts, AVRational pixel_aspect)
47 {
48  BufferSourceContext *c = buffer_filter->priv;
49 
50  if (c->buf) {
51  av_log(buffer_filter, AV_LOG_ERROR,
52  "Buffering several frames is not supported. "
53  "Please consume all available frames before adding a new one.\n"
54  );
55  //return -1;
56  }
57 
58  CHECK_PARAM_CHANGE(buffer_filter, c, frame->width, frame->height, frame->format);
59 
60  c->buf = avfilter_get_video_buffer(buffer_filter->outputs[0], AV_PERM_WRITE,
61  c->w, c->h);
62  av_image_copy(c->buf->data, c->buf->linesize, frame->data, frame->linesize,
63  c->pix_fmt, c->w, c->h);
64 
65  avfilter_copy_frame_props(c->buf, frame);
66  c->buf->pts = pts;
68 
69  return 0;
70 }
71 
73 {
74  BufferSourceContext *c = s->priv;
75 
76  if (c->buf) {
78  "Buffering several frames is not supported. "
79  "Please consume all available frames before adding a new one.\n"
80  );
81  return AVERROR(EINVAL);
82  }
83 
84  CHECK_PARAM_CHANGE(s, c, buf->video->w, buf->video->h, buf->format);
85 
86  c->buf = buf;
87 
88  return 0;
89 }
90 
91 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
92 {
93  BufferSourceContext *c = ctx->priv;
94  char pix_fmt_str[128];
95  int n = 0;
96 
97  if (!args ||
98  (n = sscanf(args, "%d:%d:%127[^:]:%d:%d:%d:%d", &c->w, &c->h, pix_fmt_str,
99  &c->time_base.num, &c->time_base.den,
100  &c->pixel_aspect.num, &c->pixel_aspect.den)) != 7) {
101  av_log(ctx, AV_LOG_ERROR, "Expected 7 arguments, but %d found in '%s'\n", n, args);
102  return AVERROR(EINVAL);
103  }
104  if ((c->pix_fmt = av_get_pix_fmt(pix_fmt_str)) == PIX_FMT_NONE) {
105  char *tail;
106  c->pix_fmt = strtol(pix_fmt_str, &tail, 10);
107  if (*tail || c->pix_fmt < 0 || c->pix_fmt >= PIX_FMT_NB) {
108  av_log(ctx, AV_LOG_ERROR, "Invalid pixel format string '%s'\n", pix_fmt_str);
109  return AVERROR(EINVAL);
110  }
111  }
112 
113  av_log(ctx, AV_LOG_INFO, "w:%d h:%d pixfmt:%s\n", c->w, c->h, av_pix_fmt_descriptors[c->pix_fmt].name);
114  return 0;
115 }
116 
117 static av_cold void uninit(AVFilterContext *ctx)
118 {
119  BufferSourceContext *s = ctx->priv;
120  if (s->buf)
122  s->buf = NULL;
123 }
124 
126 {
127  BufferSourceContext *c = ctx->priv;
128  enum PixelFormat pix_fmts[] = { c->pix_fmt, PIX_FMT_NONE };
129 
131  return 0;
132 }
133 
134 static int config_props(AVFilterLink *link)
135 {
136  BufferSourceContext *c = link->src->priv;
137 
138  link->w = c->w;
139  link->h = c->h;
141  link->time_base = c->time_base;
142 
143  return 0;
144 }
145 
146 static int request_frame(AVFilterLink *link)
147 {
148  BufferSourceContext *c = link->src->priv;
149 
150  if (!c->buf) {
151  av_log(link->src, AV_LOG_ERROR,
152  "request_frame() called with no available frame!\n");
153  //return -1;
154  }
155 
157  avfilter_draw_slice(link, 0, link->h, 1);
158  avfilter_end_frame(link);
160  c->buf = NULL;
161 
162  return 0;
163 }
164 
165 static int poll_frame(AVFilterLink *link)
166 {
167  BufferSourceContext *c = link->src->priv;
168  return !!c->buf;
169 }
170 
172  .name = "buffer",
173  .description = NULL_IF_CONFIG_SMALL("Buffer video frames, and make them accessible to the filterchain."),
174  .priv_size = sizeof(BufferSourceContext),
176 
177  .init = init,
178  .uninit = uninit,
179 
180  .inputs = (AVFilterPad[]) {{ .name = NULL }},
181  .outputs = (AVFilterPad[]) {{ .name = "default",
182  .type = AVMEDIA_TYPE_VIDEO,
183  .request_frame = request_frame,
184  .poll_frame = poll_frame,
185  .config_props = config_props, },
186  { .name = NULL}},
187 };