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ffmpeg / libavdevice / v4l2.c @ 2912e87a

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1
/*
2
 * Video4Linux2 grab interface
3
 * Copyright (c) 2000,2001 Fabrice Bellard
4
 * 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 Libav.
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 *
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 * Libav 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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 * Libav 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 Libav; 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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 */
29

    
30
#undef __STRICT_ANSI__ //workaround due to broken kernel headers
31
#include "config.h"
32
#include "libavformat/avformat.h"
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#include <unistd.h>
34
#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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#if HAVE_SYS_VIDEOIO_H
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#include <sys/videoio.h>
40
#else
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#include <asm/types.h>
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#include <linux/videodev2.h>
43
#endif
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#include <time.h>
45
#include <strings.h>
46
#include "libavutil/imgutils.h"
47

    
48
static const int desired_video_buffers = 256;
49

    
50
enum io_method {
51
    io_read,
52
    io_mmap,
53
    io_userptr
54
};
55

    
56
struct video_data {
57
    int fd;
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    int frame_format; /* V4L2_PIX_FMT_* */
59
    enum io_method io_method;
60
    int width, height;
61
    int frame_size;
62
    int top_field_first;
63

    
64
    int buffers;
65
    void **buf_start;
66
    unsigned int *buf_len;
67
};
68

    
69
struct buff_data {
70
    int index;
71
    int fd;
72
};
73

    
74
struct fmt_map {
75
    enum PixelFormat ff_fmt;
76
    enum CodecID codec_id;
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    uint32_t v4l2_fmt;
78
};
79

    
80
static struct fmt_map fmt_conversion_table[] = {
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    //ff_fmt           codec_id           v4l2_fmt
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    { PIX_FMT_YUV420P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420  },
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    { PIX_FMT_YUV422P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P },
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    { PIX_FMT_YUYV422, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUYV    },
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    { PIX_FMT_UYVY422, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_UYVY    },
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    { PIX_FMT_YUV411P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV411P },
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    { PIX_FMT_YUV410P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV410  },
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    { PIX_FMT_RGB555,  CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555  },
89
    { PIX_FMT_RGB565,  CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565  },
90
    { PIX_FMT_BGR24,   CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR24   },
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    { PIX_FMT_RGB24,   CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB24   },
92
    { PIX_FMT_BGRA,    CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR32   },
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    { PIX_FMT_GRAY8,   CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_GREY    },
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    { PIX_FMT_NV12,    CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12    },
95
    { PIX_FMT_NONE,    CODEC_ID_MJPEG,    V4L2_PIX_FMT_MJPEG   },
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    { PIX_FMT_NONE,    CODEC_ID_MJPEG,    V4L2_PIX_FMT_JPEG    },
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};
98

    
99
static int device_open(AVFormatContext *ctx, uint32_t *capabilities)
100
{
101
    struct v4l2_capability cap;
102
    int fd;
103
    int res, err;
104
    int flags = O_RDWR;
105

    
106
    if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
107
        flags |= O_NONBLOCK;
108
    }
109
    fd = open(ctx->filename, flags, 0);
110
    if (fd < 0) {
111
        av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
112
                 ctx->filename, strerror(errno));
113

    
114
        return AVERROR(errno);
115
    }
116

    
117
    res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
118
    // ENOIOCTLCMD definition only availble on __KERNEL__
119
    if (res < 0 && ((err = errno) == 515)) {
120
        av_log(ctx, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");
121
        close(fd);
122

    
123
        return AVERROR(515);
124
    }
125
    if (res < 0) {
126
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
127
                 strerror(errno));
128
        close(fd);
129

    
130
        return AVERROR(err);
131
    }
132
    if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
133
        av_log(ctx, AV_LOG_ERROR, "Not a video capture device\n");
134
        close(fd);
135

    
136
        return AVERROR(ENODEV);
137
    }
138
    *capabilities = cap.capabilities;
139

    
140
    return fd;
141
}
142

    
143
static int device_init(AVFormatContext *ctx, int *width, int *height, uint32_t pix_fmt)
144
{
145
    struct video_data *s = ctx->priv_data;
146
    int fd = s->fd;
147
    struct v4l2_format fmt;
148
    int res;
149

    
150
    memset(&fmt, 0, sizeof(struct v4l2_format));
151
    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
152
    fmt.fmt.pix.width = *width;
153
    fmt.fmt.pix.height = *height;
154
    fmt.fmt.pix.pixelformat = pix_fmt;
155
    fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
156
    res = ioctl(fd, VIDIOC_S_FMT, &fmt);
157
    if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
158
        av_log(ctx, 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);
159
        *width = fmt.fmt.pix.width;
160
        *height = fmt.fmt.pix.height;
161
    }
162

    
163
    if (pix_fmt != fmt.fmt.pix.pixelformat) {
164
        av_log(ctx, AV_LOG_DEBUG, "The V4L2 driver changed the pixel format from 0x%08X to 0x%08X\n", pix_fmt, fmt.fmt.pix.pixelformat);
165
        res = -1;
166
    }
167

    
168
    return res;
169
}
170

    
171
static int first_field(int fd)
172
{
173
    int res;
174
    v4l2_std_id std;
175

    
176
    res = ioctl(fd, VIDIOC_G_STD, &std);
177
    if (res < 0) {
178
        return 0;
179
    }
180
    if (std & V4L2_STD_NTSC) {
181
        return 0;
182
    }
183

    
184
    return 1;
185
}
186

    
187
static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt, enum CodecID codec_id)
188
{
189
    int i;
190

    
191
    for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
192
        if ((codec_id == CODEC_ID_NONE ||
193
             fmt_conversion_table[i].codec_id == codec_id) &&
194
            (pix_fmt == PIX_FMT_NONE ||
195
             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 v4l2_fmt, enum CodecID codec_id)
204
{
205
    int i;
206

    
207
    for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
208
        if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt &&
209
            fmt_conversion_table[i].codec_id == codec_id) {
210
            return fmt_conversion_table[i].ff_fmt;
211
        }
212
    }
213

    
214
    return PIX_FMT_NONE;
215
}
216

    
217
static enum CodecID fmt_v4l2codec(uint32_t v4l2_fmt)
218
{
219
    int i;
220

    
221
    for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
222
        if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt) {
223
            return fmt_conversion_table[i].codec_id;
224
        }
225
    }
226

    
227
    return CODEC_ID_NONE;
228
}
229

    
230
static int mmap_init(AVFormatContext *ctx)
231
{
232
    struct video_data *s = ctx->priv_data;
233
    struct v4l2_requestbuffers req;
234
    int i, res;
235

    
236
    memset(&req, 0, sizeof(struct v4l2_requestbuffers));
237
    req.count = desired_video_buffers;
238
    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
239
    req.memory = V4L2_MEMORY_MMAP;
240
    res = ioctl(s->fd, VIDIOC_REQBUFS, &req);
241
    if (res < 0) {
242
        if (errno == EINVAL) {
243
            av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
244
        } else {
245
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
246
        }
247

    
248
        return AVERROR(errno);
249
    }
250

    
251
    if (req.count < 2) {
252
        av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
253

    
254
        return AVERROR(ENOMEM);
255
    }
256
    s->buffers = req.count;
257
    s->buf_start = av_malloc(sizeof(void *) * s->buffers);
258
    if (s->buf_start == NULL) {
259
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
260

    
261
        return AVERROR(ENOMEM);
262
    }
263
    s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
264
    if (s->buf_len == NULL) {
265
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
266
        av_free(s->buf_start);
267

    
268
        return AVERROR(ENOMEM);
269
    }
270

    
271
    for (i = 0; i < req.count; i++) {
272
        struct v4l2_buffer buf;
273

    
274
        memset(&buf, 0, sizeof(struct v4l2_buffer));
275
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
276
        buf.memory = V4L2_MEMORY_MMAP;
277
        buf.index = i;
278
        res = ioctl(s->fd, VIDIOC_QUERYBUF, &buf);
279
        if (res < 0) {
280
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
281

    
282
            return AVERROR(errno);
283
        }
284

    
285
        s->buf_len[i] = buf.length;
286
        if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
287
            av_log(ctx, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
288

    
289
            return -1;
290
        }
291
        s->buf_start[i] = mmap (NULL, buf.length,
292
                        PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
293
        if (s->buf_start[i] == MAP_FAILED) {
294
            av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
295

    
296
            return AVERROR(errno);
297
        }
298
    }
299

    
300
    return 0;
301
}
302

    
303
static int read_init(AVFormatContext *ctx)
304
{
305
    return -1;
306
}
307

    
308
static void mmap_release_buffer(AVPacket *pkt)
309
{
310
    struct v4l2_buffer buf;
311
    int res, fd;
312
    struct buff_data *buf_descriptor = pkt->priv;
313

    
314
    if (pkt->data == NULL) {
315
         return;
316
    }
317

    
318
    memset(&buf, 0, sizeof(struct v4l2_buffer));
319
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
320
    buf.memory = V4L2_MEMORY_MMAP;
321
    buf.index = buf_descriptor->index;
322
    fd = buf_descriptor->fd;
323
    av_free(buf_descriptor);
324

    
325
    res = ioctl(fd, VIDIOC_QBUF, &buf);
326
    if (res < 0) {
327
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
328
    }
329
    pkt->data = NULL;
330
    pkt->size = 0;
331
}
332

    
333
static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
334
{
335
    struct video_data *s = ctx->priv_data;
336
    struct v4l2_buffer buf;
337
    struct buff_data *buf_descriptor;
338
    int res;
339

    
340
    memset(&buf, 0, sizeof(struct v4l2_buffer));
341
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
342
    buf.memory = V4L2_MEMORY_MMAP;
343

    
344
    /* FIXME: Some special treatment might be needed in case of loss of signal... */
345
    while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
346
    if (res < 0) {
347
        if (errno == EAGAIN) {
348
            pkt->size = 0;
349

    
350
            return AVERROR(EAGAIN);
351
        }
352
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
353

    
354
        return AVERROR(errno);
355
    }
356
    assert (buf.index < s->buffers);
357
    if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
358
        av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);
359

    
360
        return AVERROR_INVALIDDATA;
361
    }
362

    
363
    /* Image is at s->buff_start[buf.index] */
364
    pkt->data= s->buf_start[buf.index];
365
    pkt->size = buf.bytesused;
366
    pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
367
    pkt->destruct = mmap_release_buffer;
368
    buf_descriptor = av_malloc(sizeof(struct buff_data));
369
    if (buf_descriptor == NULL) {
370
        /* Something went wrong... Since av_malloc() failed, we cannot even
371
         * allocate a buffer for memcopying into it
372
         */
373
        av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
374
        res = ioctl(s->fd, VIDIOC_QBUF, &buf);
375

    
376
        return AVERROR(ENOMEM);
377
    }
378
    buf_descriptor->fd = s->fd;
379
    buf_descriptor->index = buf.index;
380
    pkt->priv = buf_descriptor;
381

    
382
    return s->buf_len[buf.index];
383
}
384

    
385
static int read_frame(AVFormatContext *ctx, AVPacket *pkt)
386
{
387
    return -1;
388
}
389

    
390
static int mmap_start(AVFormatContext *ctx)
391
{
392
    struct video_data *s = ctx->priv_data;
393
    enum v4l2_buf_type type;
394
    int i, res;
395

    
396
    for (i = 0; i < s->buffers; i++) {
397
        struct v4l2_buffer buf;
398

    
399
        memset(&buf, 0, sizeof(struct v4l2_buffer));
400
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
401
        buf.memory = V4L2_MEMORY_MMAP;
402
        buf.index  = i;
403

    
404
        res = ioctl(s->fd, VIDIOC_QBUF, &buf);
405
        if (res < 0) {
406
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
407

    
408
            return AVERROR(errno);
409
        }
410
    }
411

    
412
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
413
    res = ioctl(s->fd, VIDIOC_STREAMON, &type);
414
    if (res < 0) {
415
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
416

    
417
        return AVERROR(errno);
418
    }
419

    
420
    return 0;
421
}
422

    
423
static void mmap_close(struct video_data *s)
424
{
425
    enum v4l2_buf_type type;
426
    int i;
427

    
428
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
429
    /* We do not check for the result, because we could
430
     * not do anything about it anyway...
431
     */
432
    ioctl(s->fd, VIDIOC_STREAMOFF, &type);
433
    for (i = 0; i < s->buffers; i++) {
434
        munmap(s->buf_start[i], s->buf_len[i]);
435
    }
436
    av_free(s->buf_start);
437
    av_free(s->buf_len);
438
}
439

    
440
static int v4l2_set_parameters(AVFormatContext *s1, AVFormatParameters *ap)
441
{
442
    struct video_data *s = s1->priv_data;
443
    struct v4l2_input input;
444
    struct v4l2_standard standard;
445
    struct v4l2_streamparm streamparm = { 0 };
446
    struct v4l2_fract *tpf = &streamparm.parm.capture.timeperframe;
447
    int i;
448

    
449
    streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
450

    
451
    if (ap->channel>=0) {
452
        /* set tv video input */
453
        memset (&input, 0, sizeof (input));
454
        input.index = ap->channel;
455
        if (ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
456
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
457
            return AVERROR(EIO);
458
        }
459

    
460
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
461
               ap->channel, input.name);
462
        if (ioctl(s->fd, VIDIOC_S_INPUT, &input.index) < 0) {
463
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set input(%d) failed\n",
464
                   ap->channel);
465
            return AVERROR(EIO);
466
        }
467
    }
468

    
469
    if (ap->standard) {
470
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
471
               ap->standard);
472
        /* set tv standard */
473
        memset (&standard, 0, sizeof (standard));
474
        for(i=0;;i++) {
475
            standard.index = i;
476
            if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
477
                av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
478
                       ap->standard);
479
                return AVERROR(EIO);
480
            }
481

    
482
            if (!strcasecmp(standard.name, ap->standard)) {
483
                break;
484
            }
485
        }
486

    
487
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
488
               ap->standard, (uint64_t)standard.id);
489
        if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
490
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
491
                   ap->standard);
492
            return AVERROR(EIO);
493
        }
494
    }
495

    
496
    if (ap->time_base.num && ap->time_base.den) {
497
        av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
498
               ap->time_base.num, ap->time_base.den);
499
        tpf->numerator = ap->time_base.num;
500
        tpf->denominator = ap->time_base.den;
501
        if (ioctl(s->fd, VIDIOC_S_PARM, &streamparm) != 0) {
502
            av_log(s1, AV_LOG_ERROR,
503
                   "ioctl set time per frame(%d/%d) failed\n",
504
                   ap->time_base.num, ap->time_base.den);
505
            return AVERROR(EIO);
506
        }
507

    
508
        if (ap->time_base.den != tpf->denominator ||
509
            ap->time_base.num != tpf->numerator) {
510
            av_log(s1, AV_LOG_INFO,
511
                   "The driver changed the time per frame from %d/%d to %d/%d\n",
512
                   ap->time_base.num, ap->time_base.den,
513
                   tpf->numerator, tpf->denominator);
514
        }
515
    } else {
516
        /* if timebase value is not set in ap, read the timebase value from the driver */
517
        if (ioctl(s->fd, VIDIOC_G_PARM, &streamparm) != 0) {
518
            av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n", strerror(errno));
519
            return AVERROR(errno);
520
        }
521
    }
522
    ap->time_base.num = tpf->numerator;
523
    ap->time_base.den = tpf->denominator;
524

    
525
    return 0;
526
}
527

    
528
static uint32_t device_try_init(AVFormatContext *s1,
529
                                const AVFormatParameters *ap,
530
                                int *width,
531
                                int *height,
532
                                enum CodecID *codec_id)
533
{
534
    uint32_t desired_format = fmt_ff2v4l(ap->pix_fmt, s1->video_codec_id);
535

    
536
    if (desired_format == 0 ||
537
        device_init(s1, width, height, desired_format) < 0) {
538
        int i;
539

    
540
        desired_format = 0;
541
        for (i = 0; i<FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
542
            if (s1->video_codec_id == CODEC_ID_NONE ||
543
                fmt_conversion_table[i].codec_id == s1->video_codec_id) {
544
                desired_format = fmt_conversion_table[i].v4l2_fmt;
545
                if (device_init(s1, width, height, desired_format) >= 0) {
546
                    break;
547
                }
548
                desired_format = 0;
549
            }
550
        }
551
    }
552
    if (desired_format != 0) {
553
        *codec_id = fmt_v4l2codec(desired_format);
554
        assert(*codec_id != CODEC_ID_NONE);
555
    }
556

    
557
    return desired_format;
558
}
559

    
560
static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
561
{
562
    struct video_data *s = s1->priv_data;
563
    AVStream *st;
564
    int res;
565
    uint32_t desired_format, capabilities;
566
    enum CodecID codec_id;
567

    
568
    st = av_new_stream(s1, 0);
569
    if (!st) {
570
        return AVERROR(ENOMEM);
571
    }
572
    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
573

    
574
    s->width  = ap->width;
575
    s->height = ap->height;
576

    
577
    capabilities = 0;
578
    s->fd = device_open(s1, &capabilities);
579
    if (s->fd < 0) {
580
        return AVERROR(EIO);
581
    }
582
    av_log(s1, AV_LOG_VERBOSE, "[%d]Capabilities: %x\n", s->fd, capabilities);
583

    
584
    if (!s->width && !s->height) {
585
        struct v4l2_format fmt;
586

    
587
        av_log(s1, AV_LOG_VERBOSE, "Querying the device for the current frame size\n");
588
        fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
589
        if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
590
            av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n", strerror(errno));
591
            return AVERROR(errno);
592
        }
593
        s->width  = fmt.fmt.pix.width;
594
        s->height = fmt.fmt.pix.height;
595
        av_log(s1, AV_LOG_VERBOSE, "Setting frame size to %dx%d\n", s->width, s->height);
596
    }
597

    
598
    desired_format = device_try_init(s1, ap, &s->width, &s->height, &codec_id);
599
    if (desired_format == 0) {
600
        av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for "
601
               "codec_id %d, pix_fmt %d.\n", s1->video_codec_id, ap->pix_fmt);
602
        close(s->fd);
603

    
604
        return AVERROR(EIO);
605
    }
606
    if (av_image_check_size(s->width, s->height, 0, s1) < 0)
607
        return AVERROR(EINVAL);
608
    s->frame_format = desired_format;
609

    
610
    if (v4l2_set_parameters(s1, ap) < 0)
611
        return AVERROR(EIO);
612

    
613
    st->codec->pix_fmt = fmt_v4l2ff(desired_format, codec_id);
614
    s->frame_size = avpicture_get_size(st->codec->pix_fmt, s->width, s->height);
615
    if (capabilities & V4L2_CAP_STREAMING) {
616
        s->io_method = io_mmap;
617
        res = mmap_init(s1);
618
        if (res == 0) {
619
            res = mmap_start(s1);
620
        }
621
    } else {
622
        s->io_method = io_read;
623
        res = read_init(s1);
624
    }
625
    if (res < 0) {
626
        close(s->fd);
627

    
628
        return AVERROR(EIO);
629
    }
630
    s->top_field_first = first_field(s->fd);
631

    
632
    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
633
    st->codec->codec_id = codec_id;
634
    st->codec->width = s->width;
635
    st->codec->height = s->height;
636
    st->codec->time_base.den = ap->time_base.den;
637
    st->codec->time_base.num = ap->time_base.num;
638
    st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
639

    
640
    return 0;
641
}
642

    
643
static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
644
{
645
    struct video_data *s = s1->priv_data;
646
    int res;
647

    
648
    if (s->io_method == io_mmap) {
649
        av_init_packet(pkt);
650
        res = mmap_read_frame(s1, pkt);
651
    } else if (s->io_method == io_read) {
652
        if (av_new_packet(pkt, s->frame_size) < 0)
653
            return AVERROR(EIO);
654

    
655
        res = read_frame(s1, pkt);
656
    } else {
657
        return AVERROR(EIO);
658
    }
659
    if (res < 0) {
660
        return res;
661
    }
662

    
663
    if (s1->streams[0]->codec->coded_frame) {
664
        s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
665
        s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
666
    }
667

    
668
    return pkt->size;
669
}
670

    
671
static int v4l2_read_close(AVFormatContext *s1)
672
{
673
    struct video_data *s = s1->priv_data;
674

    
675
    if (s->io_method == io_mmap) {
676
        mmap_close(s);
677
    }
678

    
679
    close(s->fd);
680
    return 0;
681
}
682

    
683
AVInputFormat ff_v4l2_demuxer = {
684
    "video4linux2",
685
    NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
686
    sizeof(struct video_data),
687
    NULL,
688
    v4l2_read_header,
689
    v4l2_read_packet,
690
    v4l2_read_close,
691
    .flags = AVFMT_NOFILE,
692
};