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ffmpeg / libavformat / v4l2.c @ 7c7e7464

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/*
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 * Video4Linux2 grab interface
3
 * Copyright (c) 2000,2001 Fabrice Bellard.
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 * Copyright (c) 2006 Luca Abeni.
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 *
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 * Part of this file is based on the V4L2 video capture example
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 * (http://v4l2spec.bytesex.org/v4l2spec/capture.c)
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 *
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 * Thanks to Michael Niedermayer for providing the mapping between
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 * V4L2_PIX_FMT_* and PIX_FMT_*
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 *
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include "avformat.h"
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#include <unistd.h>
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#include <fcntl.h>
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#include <sys/ioctl.h>
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#include <sys/mman.h>
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#include <sys/time.h>
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#include <asm/types.h>
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#include <linux/videodev2.h>
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#include <time.h>
38

    
39
static const int desired_video_buffers = 256;
40

    
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enum io_method {
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    io_read,
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    io_mmap,
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    io_userptr
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};
46

    
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struct video_data {
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    int fd;
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    int frame_format; /* V4L2_PIX_FMT_* */
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    enum io_method io_method;
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    int width, height;
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    int frame_rate;
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    int frame_rate_base;
54
    int frame_size;
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    int top_field_first;
56

    
57
    int buffers;
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    void **buf_start;
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    unsigned int *buf_len;
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};
61

    
62
struct fmt_map {
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    enum PixelFormat ff_fmt;
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    int32_t v4l2_fmt;
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};
66

    
67
static struct fmt_map fmt_conversion_table[] = {
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    {
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        .ff_fmt = PIX_FMT_YUV420P,
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        .v4l2_fmt = V4L2_PIX_FMT_YUV420,
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    },
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    {
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        .ff_fmt = PIX_FMT_YUV422P,
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        .v4l2_fmt = V4L2_PIX_FMT_YUV422P,
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    },
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    {
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        .ff_fmt = PIX_FMT_YUV422,
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        .v4l2_fmt = V4L2_PIX_FMT_YUYV,
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    },
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    {
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        .ff_fmt = PIX_FMT_UYVY422,
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        .v4l2_fmt = V4L2_PIX_FMT_UYVY,
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    },
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    {
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        .ff_fmt = PIX_FMT_YUV411P,
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        .v4l2_fmt = V4L2_PIX_FMT_YUV411P,
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    },
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    {
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        .ff_fmt = PIX_FMT_YUV410P,
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        .v4l2_fmt = V4L2_PIX_FMT_YUV410,
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    },
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    {
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        .ff_fmt = PIX_FMT_BGR24,
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        .v4l2_fmt = V4L2_PIX_FMT_BGR24,
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    },
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    {
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        .ff_fmt = PIX_FMT_RGB24,
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        .v4l2_fmt = V4L2_PIX_FMT_RGB24,
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    },
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    /*
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    {
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        .ff_fmt = PIX_FMT_RGBA32,
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        .v4l2_fmt = V4L2_PIX_FMT_BGR32,
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    },
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    */
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    {
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        .ff_fmt = PIX_FMT_GRAY8,
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        .v4l2_fmt = V4L2_PIX_FMT_GREY,
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    },
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};
111

    
112
static int device_open(const char *devname, uint32_t *capabilities)
113
{
114
    struct v4l2_capability cap;
115
    int fd;
116
    int res;
117

    
118
    fd = open(devname, O_RDWR /*| O_NONBLOCK*/, 0);
119
    if (fd < 0) {
120
        av_log(NULL, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
121
                 devname, strerror(errno));
122

    
123
        return -1;
124
    }
125

    
126
    res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
127
    // ENOIOCTLCMD definition only availble on __KERNEL__
128
    if (res < 0 && errno == 515)
129
    {
130
        av_log(NULL, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");
131
        close(fd);
132

    
133
        return -1;
134
    }
135
    if (res < 0) {
136
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
137
                 strerror(errno));
138
        close(fd);
139

    
140
        return -1;
141
    }
142
    if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
143
        av_log(NULL, AV_LOG_ERROR, "Not a video capture device\n");
144
        close(fd);
145

    
146
        return -1;
147
    }
148
    *capabilities = cap.capabilities;
149

    
150
    return fd;
151
}
152

    
153
static int device_init(int fd, int *width, int *height, int pix_fmt)
154
{
155
    struct v4l2_format fmt;
156
    int res;
157

    
158
    memset(&fmt, 0, sizeof(struct v4l2_format));
159
    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
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    fmt.fmt.pix.width = *width;
161
    fmt.fmt.pix.height = *height;
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    fmt.fmt.pix.pixelformat = pix_fmt;
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    fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
164
    res = ioctl(fd, VIDIOC_S_FMT, &fmt);
165
    if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
166
        av_log(NULL, AV_LOG_INFO, "The V4L2 driver changed the video from %dx%d to %dx%d\n", *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
167
        *width = fmt.fmt.pix.width;
168
        *height = fmt.fmt.pix.height;
169
    }
170

    
171
    return res;
172
}
173

    
174
static int first_field(int fd)
175
{
176
    int res;
177
    v4l2_std_id std;
178

    
179
    res = ioctl(fd, VIDIOC_G_STD, &std);
180
    if (res < 0) {
181
        return 0;
182
    }
183
    if (std & V4L2_STD_NTSC) {
184
        return 0;
185
    }
186

    
187
    return 1;
188
}
189

    
190
static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt)
191
{
192
    int i;
193

    
194
    for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
195
        if (fmt_conversion_table[i].ff_fmt == pix_fmt) {
196
            return fmt_conversion_table[i].v4l2_fmt;
197
        }
198
    }
199

    
200
    return 0;
201
}
202

    
203
static enum PixelFormat fmt_v4l2ff(uint32_t pix_fmt)
204
{
205
    int i;
206

    
207
    for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
208
        if (fmt_conversion_table[i].v4l2_fmt == pix_fmt) {
209
            return fmt_conversion_table[i].ff_fmt;
210
        }
211
    }
212

    
213
    return -1;
214
}
215

    
216
static int mmap_init(struct video_data *s)
217
{
218
    struct v4l2_requestbuffers req;
219
    int i, res;
220

    
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    memset(&req, 0, sizeof(struct v4l2_requestbuffers));
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    req.count = desired_video_buffers;
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    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
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    req.memory = V4L2_MEMORY_MMAP;
225
    res = ioctl (s->fd, VIDIOC_REQBUFS, &req);
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    if (res < 0) {
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        if (errno == EINVAL) {
228
            av_log(NULL, AV_LOG_ERROR, "Device does not support mmap\n");
229
        } else {
230
            av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
231
        }
232

    
233
        return -1;
234
    }
235

    
236
    if (req.count < 2) {
237
        av_log(NULL, AV_LOG_ERROR, "Insufficient buffer memory\n");
238

    
239
        return -1;
240
    }
241
    s->buffers = req.count;
242
    s->buf_start = av_malloc(sizeof(void *) * s->buffers);
243
    if (s->buf_start == NULL) {
244
        av_log(NULL, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
245

    
246
        return -1;
247
    }
248
    s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
249
    if (s->buf_len == NULL) {
250
        av_log(NULL, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
251
        av_free(s->buf_start);
252

    
253
        return -1;
254
    }
255

    
256
    for (i = 0; i < req.count; i++) {
257
        struct v4l2_buffer buf;
258

    
259
        memset(&buf, 0, sizeof(struct v4l2_buffer));
260
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
261
        buf.memory = V4L2_MEMORY_MMAP;
262
        buf.index = i;
263
        res = ioctl (s->fd, VIDIOC_QUERYBUF, &buf);
264
        if (res < 0) {
265
            av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
266

    
267
            return -1;
268
        }
269

    
270
        s->buf_len[i] = buf.length;
271
        if (s->buf_len[i] < s->frame_size) {
272
            av_log(NULL, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
273

    
274
            return -1;
275
        }
276
        s->buf_start[i] = mmap (NULL, buf.length,
277
                        PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
278
        if (s->buf_start[i] == MAP_FAILED) {
279
            av_log(NULL, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
280

    
281
            return -1;
282
        }
283
    }
284

    
285
    return 0;
286
}
287

    
288
static int read_init(struct video_data *s)
289
{
290
    return -1;
291
}
292

    
293
static int mmap_read_frame(struct video_data *s, void *frame, int64_t *ts)
294
{
295
    struct v4l2_buffer buf;
296
    int res;
297

    
298
    memset(&buf, 0, sizeof(struct v4l2_buffer));
299
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
300
    buf.memory = V4L2_MEMORY_MMAP;
301

    
302
    /* FIXME: Some special treatment might be needed in case of loss of signal... */
303
    while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 &&
304
           ((errno == EAGAIN) || (errno == EINTR)));
305
    if (res < 0) {
306
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
307

    
308
        return -1;
309
    }
310
    assert (buf.index < s->buffers);
311
    if (buf.bytesused != s->frame_size) {
312
        av_log(NULL, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);
313

    
314
        return -1;
315
    }
316

    
317
    /* Image is at s->buff_start[buf.index] */
318
    memcpy(frame, s->buf_start[buf.index], buf.bytesused);
319
    *ts = buf.timestamp.tv_sec * int64_t_C(1000000) + buf.timestamp.tv_usec;
320

    
321
    res = ioctl (s->fd, VIDIOC_QBUF, &buf);
322
    if (res < 0) {
323
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
324

    
325
        return -1;
326
    }
327

    
328
    return s->buf_len[buf.index];
329
}
330

    
331
static int read_frame(struct video_data *s, void *frame, int64_t *ts)
332
{
333
    return -1;
334
}
335

    
336
static int mmap_start(struct video_data *s)
337
{
338
    enum v4l2_buf_type type;
339
    int i, res;
340

    
341
    for (i = 0; i < s->buffers; i++) {
342
        struct v4l2_buffer buf;
343

    
344
        memset(&buf, 0, sizeof(struct v4l2_buffer));
345
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
346
        buf.memory = V4L2_MEMORY_MMAP;
347
        buf.index  = i;
348

    
349
        res = ioctl (s->fd, VIDIOC_QBUF, &buf);
350
        if (res < 0) {
351
            av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
352

    
353
            return -1;
354
        }
355
    }
356

    
357
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
358
    res = ioctl (s->fd, VIDIOC_STREAMON, &type);
359
    if (res < 0) {
360
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
361

    
362
        return -1;
363
    }
364

    
365
    return 0;
366
}
367

    
368
static void mmap_close(struct video_data *s)
369
{
370
    enum v4l2_buf_type type;
371
    int i;
372

    
373
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
374
    /* We do not check for the result, because we could
375
     * not do anything about it anyway...
376
     */
377
    ioctl(s->fd, VIDIOC_STREAMOFF, &type);
378
    for (i = 0; i < s->buffers; i++) {
379
        munmap(s->buf_start[i], s->buf_len[i]);
380
    }
381
    av_free(s->buf_start);
382
    av_free(s->buf_len);
383
}
384

    
385
static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
386
{
387
    struct video_data *s = s1->priv_data;
388
    AVStream *st;
389
    int width, height;
390
    int res, frame_rate, frame_rate_base;
391
    uint32_t desired_format, capabilities;
392
    const char *video_device;
393

    
394
    if (ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
395
        av_log(s1, AV_LOG_ERROR, "Missing/Wrong parameters\n");
396

    
397
        return -1;
398
    }
399

    
400
    width = ap->width;
401
    height = ap->height;
402
    frame_rate = ap->time_base.den;
403
    frame_rate_base = ap->time_base.num;
404

    
405
    if((unsigned)width > 32767 || (unsigned)height > 32767) {
406
        av_log(s1, AV_LOG_ERROR, "Wrong size %dx%d\n", width, height);
407

    
408
        return -1;
409
    }
410

    
411
    st = av_new_stream(s1, 0);
412
    if (!st) {
413
        return -ENOMEM;
414
    }
415
    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
416

    
417
    s->width = width;
418
    s->height = height;
419
    s->frame_rate      = frame_rate;
420
    s->frame_rate_base = frame_rate_base;
421

    
422
    video_device = ap->device;
423
    if (!video_device) {
424
        video_device = "/dev/video";
425
    }
426
    capabilities = 0;
427
    s->fd = device_open(video_device, &capabilities);
428
    if (s->fd < 0) {
429
        av_free(st);
430

    
431
        return AVERROR_IO;
432
    }
433
    av_log(s1, AV_LOG_INFO, "[%d]Capabilities: %x\n", s->fd, capabilities);
434

    
435
    desired_format = fmt_ff2v4l(ap->pix_fmt);
436
    if (desired_format == 0 || (device_init(s->fd, &width, &height, desired_format) < 0)) {
437
        int i, done;
438

    
439
        done = 0; i = 0;
440
        while (!done) {
441
            desired_format = fmt_conversion_table[i].v4l2_fmt;
442
            if (device_init(s->fd, &width, &height, desired_format) < 0) {
443
                desired_format = 0;
444
                i++;
445
            } else {
446
               done = 1;
447
            }
448
            if (i == sizeof(fmt_conversion_table) / sizeof(struct fmt_map)) {
449
               done = 1;
450
            }
451
        }
452
    }
453
    if (desired_format == 0) {
454
        av_log(s1, AV_LOG_ERROR, "Cannot find a proper format.\n");
455
        close(s->fd);
456
        av_free(st);
457

    
458
        return AVERROR_IO;
459
    }
460
    s->frame_format = desired_format;
461

    
462
    st->codec->pix_fmt = fmt_v4l2ff(desired_format);
463
    s->frame_size = avpicture_get_size(st->codec->pix_fmt, width, height);
464
    if (capabilities & V4L2_CAP_STREAMING) {
465
        s->io_method = io_mmap;
466
        res = mmap_init(s);
467
        if (res == 0) {
468
            res = mmap_start(s);
469
        }
470
    } else {
471
        s->io_method = io_read;
472
        res = read_init(s);
473
    }
474
    if (res < 0) {
475
        close(s->fd);
476
        av_free(st);
477

    
478
        return AVERROR_IO;
479
    }
480
    s->top_field_first = first_field(s->fd);
481

    
482
    st->codec->codec_type = CODEC_TYPE_VIDEO;
483
    st->codec->codec_id = CODEC_ID_RAWVIDEO;
484
    st->codec->width = width;
485
    st->codec->height = height;
486
    st->codec->time_base.den = frame_rate;
487
    st->codec->time_base.num = frame_rate_base;
488
    st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
489

    
490
    return 0;
491
}
492

    
493
static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
494
{
495
    struct video_data *s = s1->priv_data;
496
    int res;
497

    
498
    if (av_new_packet(pkt, s->frame_size) < 0)
499
        return AVERROR_IO;
500

    
501
    if (s->io_method == io_mmap) {
502
        res = mmap_read_frame(s, pkt->data, &pkt->pts);
503
    } else if (s->io_method == io_read) {
504
        res = read_frame(s, pkt->data, &pkt->pts);
505
    } else {
506
        return AVERROR_IO;
507
    }
508
    if (res < 0) {
509
        return AVERROR_IO;
510
    }
511

    
512
    if (s1->streams[0]->codec->coded_frame) {
513
        s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
514
        s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
515
    }
516

    
517
    return s->frame_size;
518
}
519

    
520
static int v4l2_read_close(AVFormatContext *s1)
521
{
522
    struct video_data *s = s1->priv_data;
523

    
524
    if (s->io_method == io_mmap) {
525
        mmap_close(s);
526
    }
527

    
528
    close(s->fd);
529
    return 0;
530
}
531

    
532
AVInputFormat v4l2_demuxer = {
533
    "video4linux2",
534
    "video grab",
535
    sizeof(struct video_data),
536
    NULL,
537
    v4l2_read_header,
538
    v4l2_read_packet,
539
    v4l2_read_close,
540
    .flags = AVFMT_NOFILE,
541
};