Libav
video.c
Go to the documentation of this file.
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/buffer.h"
23 #include "libavutil/imgutils.h"
24 #include "libavutil/mem.h"
25 
26 #include "avfilter.h"
27 #include "internal.h"
28 #include "video.h"
29 
31 {
32  return ff_get_video_buffer(link->dst->outputs[0], w, h);
33 }
34 
35 /* TODO: set the buffer's priv member to a context structure for the whole
36  * filter chain. This will allow for a buffer pool instead of the constant
37  * alloc & free cycle currently implemented. */
39 {
40  AVFrame *frame = av_frame_alloc();
41  int ret;
42 
43  if (!frame)
44  return NULL;
45 
46  frame->width = w;
47  frame->height = h;
48  frame->format = link->format;
49 
50  ret = av_frame_get_buffer(frame, 32);
51  if (ret < 0)
52  av_frame_free(&frame);
53 
54  return frame;
55 }
56 
57 #if FF_API_AVFILTERBUFFER
58 AVFilterBufferRef *
59 avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
60  int w, int h, enum AVPixelFormat format)
61 {
62  AVFilterBuffer *pic = av_mallocz(sizeof(AVFilterBuffer));
63  AVFilterBufferRef *picref = av_mallocz(sizeof(AVFilterBufferRef));
64 
65  if (!pic || !picref)
66  goto fail;
67 
68  picref->buf = pic;
69  picref->buf->free = ff_avfilter_default_free_buffer;
70  if (!(picref->video = av_mallocz(sizeof(AVFilterBufferRefVideoProps))))
71  goto fail;
72 
73  pic->w = picref->video->w = w;
74  pic->h = picref->video->h = h;
75 
76  /* make sure the buffer gets read permission or it's useless for output */
77  picref->perms = perms | AV_PERM_READ;
78 
79  pic->refcount = 1;
80  picref->type = AVMEDIA_TYPE_VIDEO;
81  pic->format = picref->format = format;
82 
83  memcpy(pic->data, data, 4*sizeof(data[0]));
84  memcpy(pic->linesize, linesize, 4*sizeof(linesize[0]));
85  memcpy(picref->data, pic->data, sizeof(picref->data));
86  memcpy(picref->linesize, pic->linesize, sizeof(picref->linesize));
87 
88  pic-> extended_data = pic->data;
89  picref->extended_data = picref->data;
90 
91  picref->pts = AV_NOPTS_VALUE;
92 
93  return picref;
94 
95 fail:
96  if (picref && picref->video)
97  av_free(picref->video);
98  av_free(picref);
99  av_free(pic);
100  return NULL;
101 }
102 #endif
103 
105 {
106  AVFrame *ret = NULL;
107 
109 
110  if (link->dstpad->get_video_buffer)
111  ret = link->dstpad->get_video_buffer(link, w, h);
112 
113  if (!ret)
114  ret = ff_default_get_video_buffer(link, w, h);
115 
116  return ret;
117 }
static AVFrame * get_video_buffer(AVFilterLink *inlink, int w, int h)
Definition: vf_pad.c:250
This structure describes decoded (raw) audio or video data.
Definition: frame.h:135
misc image utilities
Main libavfilter public API header.
memory handling functions
AVFrame * ff_null_get_video_buffer(AVFilterLink *link, int w, int h)
Definition: video.c:30
AVFrame * ff_get_video_buffer(AVFilterLink *link, int w, int h)
Request a picture buffer with a specific set of permissions.
Definition: video.c:104
void ff_avfilter_default_free_buffer(AVFilterBuffer *ptr)
default handler for freeing audio/video buffer when there are no references left
Definition: buffer.c:30
void ff_dlog_link(void *ctx, AVFilterLink *link, int end)
Definition: avfilter.c:225
uint8_t
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:57
const char data[16]
Definition: mxf.c:70
int width
width and height of the video frame
Definition: frame.h:174
void av_free(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc(). ...
Definition: mem.c:186
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:69
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames...
Definition: frame.h:186
NULL
Definition: eval.c:55
refcounted data buffer API
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:578
int av_frame_get_buffer(AVFrame *frame, int align)
Allocate new buffer(s) for audio or video data.
Definition: frame.c:175
AVFrame * ff_default_get_video_buffer(AVFilterLink *link, int w, int h)
Definition: video.c:38
AVFilterBufferRef * avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms, int w, int h, enum AVPixelFormat format)
Definition: video.c:59
#define FF_DPRINTF_START(ctx, func)
Definition: internal.h:148
int height
Definition: frame.h:174
internal API functions
AVPixelFormat
Pixel format.
Definition: pixfmt.h:63
void * av_mallocz(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:205
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:228