video.c
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1 /*
2  * This file is part of Libav.
3  *
4  * Libav is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * Libav is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with Libav; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include <string.h>
20 #include <stdio.h>
21 
22 #include "libavutil/imgutils.h"
23 #include "libavutil/mem.h"
24 
25 #include "avfilter.h"
26 #include "internal.h"
27 #include "video.h"
28 
29 #ifdef DEBUG
30 static char *ff_get_ref_perms_string(char *buf, size_t buf_size, int perms)
31 {
32  snprintf(buf, buf_size, "%s%s%s%s%s%s",
33  perms & AV_PERM_READ ? "r" : "",
34  perms & AV_PERM_WRITE ? "w" : "",
35  perms & AV_PERM_PRESERVE ? "p" : "",
36  perms & AV_PERM_REUSE ? "u" : "",
37  perms & AV_PERM_REUSE2 ? "U" : "",
38  perms & AV_PERM_NEG_LINESIZES ? "n" : "");
39  return buf;
40 }
41 #endif
42 
43 static void ff_dlog_ref(void *ctx, AVFilterBufferRef *ref, int end)
44 {
45  av_unused char buf[16];
46  av_dlog(ctx,
47  "ref[%p buf:%p refcount:%d perms:%s data:%p linesize[%d, %d, %d, %d] pts:%"PRId64" pos:%"PRId64,
48  ref, ref->buf, ref->buf->refcount, ff_get_ref_perms_string(buf, sizeof(buf), ref->perms), ref->data[0],
49  ref->linesize[0], ref->linesize[1], ref->linesize[2], ref->linesize[3],
50  ref->pts, ref->pos);
51 
52  if (ref->video) {
53  av_dlog(ctx, " a:%d/%d s:%dx%d i:%c iskey:%d type:%c",
55  ref->video->w, ref->video->h,
56  !ref->video->interlaced ? 'P' : /* Progressive */
57  ref->video->top_field_first ? 'T' : 'B', /* Top / Bottom */
58  ref->video->key_frame,
60  }
61  if (ref->audio) {
62  av_dlog(ctx, " cl:%"PRId64"d n:%d r:%d p:%d",
63  ref->audio->channel_layout,
64  ref->audio->nb_samples,
65  ref->audio->sample_rate,
66  ref->audio->planar);
67  }
68 
69  av_dlog(ctx, "]%s", end ? "\n" : "");
70 }
71 
73 {
74  return ff_get_video_buffer(link->dst->outputs[0], perms, w, h);
75 }
76 
77 /* TODO: set the buffer's priv member to a context structure for the whole
78  * filter chain. This will allow for a buffer pool instead of the constant
79  * alloc & free cycle currently implemented. */
81 {
82  int linesize[4];
83  uint8_t *data[4];
84  AVFilterBufferRef *picref = NULL;
85 
86  // +2 is needed for swscaler, +16 to be SIMD-friendly
87  if (av_image_alloc(data, linesize, w, h, link->format, 16) < 0)
88  return NULL;
89 
90  picref = avfilter_get_video_buffer_ref_from_arrays(data, linesize,
91  perms, w, h, link->format);
92  if (!picref) {
93  av_free(data[0]);
94  return NULL;
95  }
96 
97  return picref;
98 }
99 
102  int w, int h, enum AVPixelFormat format)
103 {
104  AVFilterBuffer *pic = av_mallocz(sizeof(AVFilterBuffer));
106 
107  if (!pic || !picref)
108  goto fail;
109 
110  picref->buf = pic;
112  if (!(picref->video = av_mallocz(sizeof(AVFilterBufferRefVideoProps))))
113  goto fail;
114 
115  pic->w = picref->video->w = w;
116  pic->h = picref->video->h = h;
117 
118  /* make sure the buffer gets read permission or it's useless for output */
119  picref->perms = perms | AV_PERM_READ;
120 
121  pic->refcount = 1;
122  picref->type = AVMEDIA_TYPE_VIDEO;
123  pic->format = picref->format = format;
124 
125  memcpy(pic->data, data, 4*sizeof(data[0]));
126  memcpy(pic->linesize, linesize, 4*sizeof(linesize[0]));
127  memcpy(picref->data, pic->data, sizeof(picref->data));
128  memcpy(picref->linesize, pic->linesize, sizeof(picref->linesize));
129 
130  pic-> extended_data = pic->data;
131  picref->extended_data = picref->data;
132 
133  picref->pts = AV_NOPTS_VALUE;
134 
135  return picref;
136 
137 fail:
138  if (picref && picref->video)
139  av_free(picref->video);
140  av_free(picref);
141  av_free(pic);
142  return NULL;
143 }
144 
145 AVFilterBufferRef *ff_get_video_buffer(AVFilterLink *link, int perms, int w, int h)
146 {
147  AVFilterBufferRef *ret = NULL;
148 
149  av_unused char buf[16];
151  av_dlog(NULL, " perms:%s w:%d h:%d\n", ff_get_ref_perms_string(buf, sizeof(buf), perms), w, h);
152 
153  if (link->dstpad->get_video_buffer)
154  ret = link->dstpad->get_video_buffer(link, perms, w, h);
155 
156  if (!ret)
157  ret = ff_default_get_video_buffer(link, perms, w, h);
158 
159  if (ret)
160  ret->type = AVMEDIA_TYPE_VIDEO;
161 
162  FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " returning "); ff_dlog_ref(NULL, ret, 1);
163 
164  return ret;
165 }