FFmpeg
xv.c
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1 /*
2  * Copyright (c) 2013 Jeff Moguillansky
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  * XVideo output device
24  *
25  * TODO:
26  * - add support to more formats
27  */
28 
29 #include <X11/Xlib.h>
30 #include <X11/extensions/Xv.h>
31 #include <X11/extensions/XShm.h>
32 #include <X11/extensions/Xvlib.h>
33 #include <sys/shm.h>
34 
35 #include "libavutil/opt.h"
36 #include "libavutil/pixdesc.h"
37 #include "libavutil/imgutils.h"
38 #include "libavformat/internal.h"
39 #include "avdevice.h"
40 
41 typedef struct {
42  AVClass *class;
43  GC gc;
44 
45  Window window;
46  int64_t window_id;
47  char *window_title;
48  int window_width, window_height;
49  int window_x, window_y;
50  int dest_x, dest_y; /**< display area position */
51  unsigned int dest_w, dest_h; /**< display area dimensions */
52 
53  Display* display;
54  char *display_name;
55 
56  XvImage* yuv_image;
57  enum AVPixelFormat image_format;
58  int image_width, image_height;
59  XShmSegmentInfo yuv_shminfo;
60  int xv_port;
62 } XVContext;
63 
64 typedef struct XVTagFormatMap
65 {
66  int tag;
69 
70 static const XVTagFormatMap tag_codec_map[] = {
71  { MKTAG('I','4','2','0'), AV_PIX_FMT_YUV420P },
72  { MKTAG('U','Y','V','Y'), AV_PIX_FMT_UYVY422 },
73  { MKTAG('Y','U','Y','2'), AV_PIX_FMT_YUYV422 },
74  { 0, AV_PIX_FMT_NONE }
75 };
76 
78 {
79  const XVTagFormatMap *m = tag_codec_map;
80  int i;
81  for (i = 0; m->tag; m = &tag_codec_map[++i]) {
82  if (m->format == format)
83  return m->tag;
84  }
85  return 0;
86 }
87 
89 {
90  XVContext *xv = s->priv_data;
91  if (xv->display) {
92  XShmDetach(xv->display, &xv->yuv_shminfo);
93  if (xv->yuv_image)
94  shmdt(xv->yuv_image->data);
95  XFree(xv->yuv_image);
96  if (xv->gc)
97  XFreeGC(xv->display, xv->gc);
98  XCloseDisplay(xv->display);
99  }
100  return 0;
101 }
102 
104 {
105  XVContext *xv = s->priv_data;
106  unsigned int num_adaptors;
107  XvAdaptorInfo *ai;
108  XvImageFormatValues *fv;
109  XColor fgcolor;
110  XWindowAttributes window_attrs;
111  int num_formats = 0, j, tag, ret;
112  AVCodecParameters *par = s->streams[0]->codecpar;
113 
114  if ( s->nb_streams > 1
115  || par->codec_type != AVMEDIA_TYPE_VIDEO
117  av_log(s, AV_LOG_ERROR, "Only a single raw or wrapped avframe video stream is supported.\n");
118  return AVERROR(EINVAL);
119  }
120 
121  if (!(tag = xv_get_tag_from_format(par->format))) {
123  "Unsupported pixel format '%s', only yuv420p, uyvy422, yuyv422 are currently supported\n",
125  return AVERROR_PATCHWELCOME;
126  }
127  xv->image_format = par->format;
128 
129  xv->display = XOpenDisplay(xv->display_name);
130  if (!xv->display) {
131  av_log(s, AV_LOG_ERROR, "Could not open the X11 display '%s'\n", xv->display_name);
132  return AVERROR(EINVAL);
133  }
134 
135  xv->image_width = par->width;
136  xv->image_height = par->height;
137  if (!xv->window_width && !xv->window_height) {
138  AVRational sar = par->sample_aspect_ratio;
139  xv->window_width = par->width;
140  xv->window_height = par->height;
141  if (sar.num) {
142  if (sar.num > sar.den)
143  xv->window_width = av_rescale(xv->window_width, sar.num, sar.den);
144  if (sar.num < sar.den)
145  xv->window_height = av_rescale(xv->window_height, sar.den, sar.num);
146  }
147  }
148  if (!xv->window_id) {
149  xv->window = XCreateSimpleWindow(xv->display, DefaultRootWindow(xv->display),
150  xv->window_x, xv->window_y,
151  xv->window_width, xv->window_height,
152  0, 0, 0);
153  if (!xv->window_title) {
154  if (!(xv->window_title = av_strdup(s->url))) {
155  ret = AVERROR(ENOMEM);
156  goto fail;
157  }
158  }
159  XStoreName(xv->display, xv->window, xv->window_title);
160  xv->wm_delete_message = XInternAtom(xv->display, "WM_DELETE_WINDOW", False);
161  XSetWMProtocols(xv->display, xv->window, &xv->wm_delete_message, 1);
162  XMapWindow(xv->display, xv->window);
163  } else
164  xv->window = xv->window_id;
165 
166  if (XvQueryAdaptors(xv->display, DefaultRootWindow(xv->display), &num_adaptors, &ai) != Success) {
168  goto fail;
169  }
170  if (!num_adaptors) {
171  av_log(s, AV_LOG_ERROR, "No X-Video adaptors present\n");
172  return AVERROR(ENODEV);
173  }
174  xv->xv_port = ai[0].base_id;
175  XvFreeAdaptorInfo(ai);
176 
177  fv = XvListImageFormats(xv->display, xv->xv_port, &num_formats);
178  if (!fv) {
180  goto fail;
181  }
182  for (j = 0; j < num_formats; j++) {
183  if (fv[j].id == tag) {
184  break;
185  }
186  }
187  XFree(fv);
188 
189  if (j >= num_formats) {
191  "Device does not support pixel format %s, aborting\n",
193  ret = AVERROR(EINVAL);
194  goto fail;
195  }
196 
197  xv->gc = XCreateGC(xv->display, xv->window, 0, 0);
198  xv->image_width = par->width;
199  xv->image_height = par->height;
200  xv->yuv_image = XvShmCreateImage(xv->display, xv->xv_port, tag, 0,
201  xv->image_width, xv->image_height, &xv->yuv_shminfo);
202  xv->yuv_shminfo.shmid = shmget(IPC_PRIVATE, xv->yuv_image->data_size,
203  IPC_CREAT | 0777);
204  xv->yuv_shminfo.shmaddr = (char *)shmat(xv->yuv_shminfo.shmid, 0, 0);
205  xv->yuv_image->data = xv->yuv_shminfo.shmaddr;
206  xv->yuv_shminfo.readOnly = False;
207 
208  XShmAttach(xv->display, &xv->yuv_shminfo);
209  XSync(xv->display, False);
210  shmctl(xv->yuv_shminfo.shmid, IPC_RMID, 0);
211 
212  XGetWindowAttributes(xv->display, xv->window, &window_attrs);
213  fgcolor.red = fgcolor.green = fgcolor.blue = 0;
214  fgcolor.flags = DoRed | DoGreen | DoBlue;
215  XAllocColor(xv->display, window_attrs.colormap, &fgcolor);
216  XSetForeground(xv->display, xv->gc, fgcolor.pixel);
217  //force display area recalculation at first frame
218  xv->window_width = xv->window_height = 0;
219 
220  return 0;
221  fail:
223  return ret;
224 }
225 
227 {
228  XVContext *xv = s->priv_data;
229  AVRational sar, dar; /* sample and display aspect ratios */
230  AVStream *st = s->streams[0];
231  AVCodecParameters *par = st->codecpar;
232 
233  /* compute overlay width and height from the codec context information */
234  sar = st->sample_aspect_ratio.num ? st->sample_aspect_ratio : (AVRational){ 1, 1 };
235  dar = av_mul_q(sar, (AVRational){ par->width, par->height });
236 
237  /* we suppose the screen has a 1/1 sample aspect ratio */
238  /* fit in the window */
239  if (av_cmp_q(dar, (AVRational){ xv->dest_w, xv->dest_h }) > 0) {
240  /* fit in width */
241  xv->dest_y = xv->dest_h;
242  xv->dest_x = 0;
243  xv->dest_h = av_rescale(xv->dest_w, dar.den, dar.num);
244  xv->dest_y -= xv->dest_h;
245  xv->dest_y /= 2;
246  } else {
247  /* fit in height */
248  xv->dest_x = xv->dest_w;
249  xv->dest_y = 0;
250  xv->dest_w = av_rescale(xv->dest_h, dar.num, dar.den);
251  xv->dest_x -= xv->dest_w;
252  xv->dest_x /= 2;
253  }
254 }
255 
257 {
258  XVContext *xv = s->priv_data;
259  XWindowAttributes window_attrs;
260 
261  XGetWindowAttributes(xv->display, xv->window, &window_attrs);
262  if (window_attrs.width != xv->window_width || window_attrs.height != xv->window_height) {
263  XRectangle rect[2];
264  xv->dest_w = window_attrs.width;
265  xv->dest_h = window_attrs.height;
267  if (xv->dest_x) {
268  rect[0].width = rect[1].width = xv->dest_x;
269  rect[0].height = rect[1].height = window_attrs.height;
270  rect[0].y = rect[1].y = 0;
271  rect[0].x = 0;
272  rect[1].x = xv->dest_w + xv->dest_x;
273  XFillRectangles(xv->display, xv->window, xv->gc, rect, 2);
274  }
275  if (xv->dest_y) {
276  rect[0].width = rect[1].width = window_attrs.width;
277  rect[0].height = rect[1].height = xv->dest_y;
278  rect[0].x = rect[1].x = 0;
279  rect[0].y = 0;
280  rect[1].y = xv->dest_h + xv->dest_y;
281  XFillRectangles(xv->display, xv->window, xv->gc, rect, 2);
282  }
283  }
284 
285  if (XvShmPutImage(xv->display, xv->xv_port, xv->window, xv->gc,
286  xv->yuv_image, 0, 0, xv->image_width, xv->image_height,
287  xv->dest_x, xv->dest_y, xv->dest_w, xv->dest_h, True) != Success) {
288  av_log(s, AV_LOG_ERROR, "Could not copy image to XV shared memory buffer\n");
289  return AVERROR_EXTERNAL;
290  }
291  return 0;
292 }
293 
294 static int write_picture(AVFormatContext *s, uint8_t *input_data[4],
295  int linesize[4])
296 {
297  XVContext *xv = s->priv_data;
298  XvImage *img = xv->yuv_image;
299  uint8_t *data[4] = {
300  img->data + img->offsets[0],
301  img->data + img->offsets[1],
302  img->data + img->offsets[2]
303  };
304 
305  /* Check messages. Window might get closed. */
306  if (!xv->window_id) {
307  XEvent event;
308  while (XPending(xv->display)) {
309  XNextEvent(xv->display, &event);
310  if (event.type == ClientMessage && event.xclient.data.l[0] == xv->wm_delete_message) {
311  av_log(xv, AV_LOG_DEBUG, "Window close event.\n");
312  return AVERROR(EPIPE);
313  }
314  }
315  }
316 
317  av_image_copy(data, img->pitches, (const uint8_t **)input_data, linesize,
318  xv->image_format, img->width, img->height);
319  return xv_repaint(s);
320 }
321 
323 {
324  AVCodecParameters *par = s->streams[0]->codecpar;
325 
327  AVFrame *frame = (AVFrame *)pkt->data;
328  return write_picture(s, frame->data, frame->linesize);
329  } else {
330  uint8_t *data[4];
331  int linesize[4];
332 
333  av_image_fill_arrays(data, linesize, pkt->data, par->format,
334  par->width, par->height, 1);
335  return write_picture(s, data, linesize);
336  }
337 }
338 
339 static int xv_write_frame(AVFormatContext *s, int stream_index, AVFrame **frame,
340  unsigned flags)
341 {
342  /* xv_write_header() should have accepted only supported formats */
344  return 0;
345  return write_picture(s, (*frame)->data, (*frame)->linesize);
346 }
347 
348 static int xv_control_message(AVFormatContext *s, int type, void *data, size_t data_size)
349 {
350  switch(type) {
352  return xv_repaint(s);
353  default:
354  break;
355  }
356  return AVERROR(ENOSYS);
357 }
358 
359 #define OFFSET(x) offsetof(XVContext, x)
360 static const AVOption options[] = {
361  { "display_name", "set display name", OFFSET(display_name), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
362  { "window_id", "set existing window id", OFFSET(window_id), AV_OPT_TYPE_INT64, {.i64 = 0 }, 0, INT64_MAX, AV_OPT_FLAG_ENCODING_PARAM },
363  { "window_size", "set window forced size", OFFSET(window_width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
364  { "window_title", "set window title", OFFSET(window_title), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
365  { "window_x", "set window x offset", OFFSET(window_x), AV_OPT_TYPE_INT, {.i64 = 0 }, -INT_MAX, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
366  { "window_y", "set window y offset", OFFSET(window_y), AV_OPT_TYPE_INT, {.i64 = 0 }, -INT_MAX, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
367  { NULL }
368 
369 };
370 
371 static const AVClass xv_class = {
372  .class_name = "xvideo outdev",
373  .item_name = av_default_item_name,
374  .option = options,
375  .version = LIBAVUTIL_VERSION_INT,
377 };
378 
380  .name = "xv",
381  .long_name = NULL_IF_CONFIG_SMALL("XV (XVideo) output device"),
382  .priv_data_size = sizeof(XVContext),
383  .audio_codec = AV_CODEC_ID_NONE,
384  .video_codec = AV_CODEC_ID_WRAPPED_AVFRAME,
387  .write_uncoded_frame = xv_write_frame,
389  .control_message = xv_control_message,
391  .priv_class = &xv_class,
392 };
xv_repaint
static int xv_repaint(AVFormatContext *s)
Definition: xv.c:256
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
AVOutputFormat::name
const char * name
Definition: avformat.h:496
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
AVFMT_VARIABLE_FPS
#define AVFMT_VARIABLE_FPS
Format allows variable fps.
Definition: avformat.h:470
rect
Definition: f_ebur128.c:77
AVFMT_NOTIMESTAMPS
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:467
rect::y
int y
Definition: f_ebur128.c:77
AV_CODEC_ID_RAWVIDEO
@ AV_CODEC_ID_RAWVIDEO
Definition: codec_id.h:63
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
pixdesc.h
AVPacket::data
uint8_t * data
Definition: packet.h:373
AVOption
AVOption.
Definition: opt.h:247
data
const char data[16]
Definition: mxf.c:143
XVTagFormatMap::format
enum AVPixelFormat format
Definition: xv.c:67
AV_APP_TO_DEV_WINDOW_REPAINT
@ AV_APP_TO_DEV_WINDOW_REPAINT
Repaint request message.
Definition: avdevice.h:144
compute_display_area
static void compute_display_area(AVFormatContext *s)
Definition: xv.c:226
XVContext::yuv_shminfo
XShmSegmentInfo yuv_shminfo
Definition: xv.c:59
xv_control_message
static int xv_control_message(AVFormatContext *s, int type, void *data, size_t data_size)
Definition: xv.c:348
options
static const AVOption options[]
Definition: xv.c:360
XVContext::window_width
int window_width
Definition: xv.c:48
xv_write_packet
static int xv_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: xv.c:322
fail
#define fail()
Definition: checkasm.h:127
xv_get_tag_from_format
static int xv_get_tag_from_format(enum AVPixelFormat format)
Definition: xv.c:77
XVTagFormatMap
Definition: xv.c:64
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
XVContext::gc
GC gc
Definition: xv.c:43
Atom
Definition: r3d.c:35
AVRational::num
int num
Numerator.
Definition: rational.h:59
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
ff_xv_muxer
const AVOutputFormat ff_xv_muxer
Definition: xv.c:379
XVContext::display
Display * display
Definition: xv.c:53
s
#define s(width, name)
Definition: cbs_vp9.c:257
AV_OPT_FLAG_ENCODING_PARAM
#define AV_OPT_FLAG_ENCODING_PARAM
a generic parameter which can be set by the user for muxing or encoding
Definition: opt.h:277
AVCodecParameters::sample_aspect_ratio
AVRational sample_aspect_ratio
Video only.
Definition: codec_par.h:136
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:126
XVContext::xv_port
int xv_port
Definition: xv.c:60
AV_OPT_TYPE_INT64
@ AV_OPT_TYPE_INT64
Definition: opt.h:225
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:201
XVContext::window
Window window
Definition: xv.c:45
AV_PIX_FMT_YUV420P
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
AV_CODEC_ID_WRAPPED_AVFRAME
@ AV_CODEC_ID_WRAPPED_AVFRAME
Passthrough codec, AVFrames wrapped in AVPacket.
Definition: codec_id.h:572
window_title
static const char * window_title
Definition: ffplay.c:311
AVFormatContext
Format I/O context.
Definition: avformat.h:1109
internal.h
xv_write_frame
static int xv_write_frame(AVFormatContext *s, int stream_index, AVFrame **frame, unsigned flags)
Definition: xv.c:339
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1004
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:64
write_trailer
static int write_trailer(AVFormatContext *s1)
Definition: v4l2enc.c:98
AV_PIX_FMT_YUYV422
@ AV_PIX_FMT_YUYV422
packed YUV 4:2:2, 16bpp, Y0 Cb Y1 Cr
Definition: pixfmt.h:67
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AV_OPT_TYPE_IMAGE_SIZE
@ AV_OPT_TYPE_IMAGE_SIZE
offset must point to two consecutive integers
Definition: opt.h:234
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT
@ AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT
Definition: log.h:40
XVContext::image_format
enum AVPixelFormat image_format
Definition: xv.c:57
XVTagFormatMap::tag
int tag
Definition: xv.c:66
XVContext::window_x
int window_x
Definition: xv.c:49
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
av_image_fill_arrays
int av_image_fill_arrays(uint8_t *dst_data[4], int dst_linesize[4], const uint8_t *src, enum AVPixelFormat pix_fmt, int width, int height, int align)
Setup the data pointers and linesizes based on the specified image parameters and the provided array.
Definition: imgutils.c:446
write_picture
static int write_picture(AVFormatContext *s, uint8_t *input_data[4], int linesize[4])
Definition: xv.c:294
AVFMT_NOFILE
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:463
AVStream::sample_aspect_ratio
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown)
Definition: avformat.h:913
avdevice.h
img
#define img
Definition: vf_colormatrix.c:116
AVERROR_EXTERNAL
#define AVERROR_EXTERNAL
Generic error in an external library.
Definition: error.h:59
XVContext::window_id
int64_t window_id
Definition: xv.c:46
xv_write_trailer
static int xv_write_trailer(AVFormatContext *s)
Definition: xv.c:88
rect::x
int x
Definition: f_ebur128.c:77
input_data
static void input_data(MLPEncodeContext *ctx, void *samples)
Wrapper function for inputting data in two different bit-depths.
Definition: mlpenc.c:1214
XVContext::display_name
char * display_name
Definition: xv.c:54
write_packet
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:731
XVContext::dest_x
int dest_x
Definition: xv.c:50
XVContext::wm_delete_message
Atom wm_delete_message
Definition: xv.c:61
XVContext::dest_w
unsigned int dest_w
Definition: xv.c:51
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:48
AVOutputFormat
Definition: avformat.h:495
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
AVCodecParameters::height
int height
Definition: codec_par.h:127
XVContext::window_title
char * window_title
Definition: xv.c:47
XVContext::window_y
int window_y
Definition: xv.c:49
av_rescale
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
Definition: mathematics.c:128
XVContext
Definition: xv.c:41
av_cmp_q
static int av_cmp_q(AVRational a, AVRational b)
Compare two rationals.
Definition: rational.h:89
tag
uint32_t tag
Definition: movenc.c:1595
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:857
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:71
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
XVContext::yuv_image
XvImage * yuv_image
Definition: xv.c:56
tag_codec_map
static const XVTagFormatMap tag_codec_map[]
Definition: xv.c:70
XVContext::dest_h
unsigned int dest_h
display area dimensions
Definition: xv.c:51
xv_class
static const AVClass xv_class
Definition: xv.c:371
AV_PIX_FMT_UYVY422
@ AV_PIX_FMT_UYVY422
packed YUV 4:2:2, 16bpp, Cb Y0 Cr Y1
Definition: pixfmt.h:81
av_image_copy
void av_image_copy(uint8_t *dst_data[4], int dst_linesizes[4], const uint8_t *src_data[4], const int src_linesizes[4], enum AVPixelFormat pix_fmt, int width, int height)
Copy image in src_data to dst_data.
Definition: imgutils.c:422
AVRational::den
int den
Denominator.
Definition: rational.h:60
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:65
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:224
av_mul_q
AVRational av_mul_q(AVRational b, AVRational c)
Multiply two rationals.
Definition: rational.c:80
av_strdup
char * av_strdup(const char *s)
Duplicate a string.
Definition: mem.c:279
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVCodecParameters::format
int format
Definition: codec_par.h:84
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
XVContext::image_height
int image_height
Definition: xv.c:58
AVPacket
This structure stores compressed data.
Definition: packet.h:350
AV_WRITE_UNCODED_FRAME_QUERY
@ AV_WRITE_UNCODED_FRAME_QUERY
Query whether the feature is possible on this stream.
Definition: internal.h:868
format
fg outputs[0] format
Definition: ffmpeg_filter.c:175
imgutils.h
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Definition: opt.h:228
write_header
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:347
xv_write_header
static int xv_write_header(AVFormatContext *s)
Definition: xv.c:103
OFFSET
#define OFFSET(x)
Definition: xv.c:359
XVContext::window_height
int window_height
Definition: xv.c:48
av_get_pix_fmt_name
const char * av_get_pix_fmt_name(enum AVPixelFormat pix_fmt)
Return the short name for a pixel format, NULL in case pix_fmt is unknown.
Definition: pixdesc.c:2484
XVContext::image_width
int image_width
Definition: xv.c:58
XVContext::dest_y
int dest_y
display area position
Definition: xv.c:50