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ffmpeg / libavformat / v4l2.c @ c04c3282

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/*
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 * Video4Linux2 grab interface
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 * 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 library 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 of the License, or (at your option) any later version.
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 *
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 * This library 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 this library; 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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#define _LINUX_TIME_H 1
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#include <linux/videodev.h>
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#include <time.h>
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static const int desired_video_buffers = 256;
38

    
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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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};
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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;
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    int frame_size;
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    int top_field_first;
54

    
55
    int buffers;
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    void **buf_start;
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    unsigned int *buf_len;
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};
59

    
60
struct fmt_map {
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    enum PixelFormat ff_fmt;
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    int32_t v4l2_fmt;
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};
64

    
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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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};
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static int device_open(const char *devname, uint32_t *capabilities)
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{
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    struct v4l2_capability cap;
113
    int fd;
114
    int res;
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    fd = open(devname, O_RDWR /*| O_NONBLOCK*/, 0);
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    if (fd < 0) {
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        av_log(NULL, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
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                 devname, strerror(errno));
120

    
121
        return -1;
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    }
123

    
124
    res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
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    // ENOIOCTLCMD definition only availble on __KERNEL__
126
    if (res < 0 && errno == 515)
127
    {
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        av_log(NULL, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");
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        close(fd);
130

    
131
        return -1;
132
    }
133
    if (res < 0) {
134
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
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                 strerror(errno));
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        close(fd);
137

    
138
        return -1;
139
    }
140
    if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
141
        av_log(NULL, AV_LOG_ERROR, "Not a video capture device\n");
142
        close(fd);
143

    
144
        return -1;
145
    }
146
    *capabilities = cap.capabilities;
147

    
148
    return fd;
149
}
150

    
151
static int device_init(int fd, int *width, int *height, int pix_fmt)
152
{
153
    struct v4l2_format fmt;
154
    int res;
155

    
156
    memset(&fmt, 0, sizeof(struct v4l2_format));
157
    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
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    fmt.fmt.pix.width = *width;
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    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;
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    res = ioctl(fd, VIDIOC_S_FMT, &fmt);
163
    if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
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        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);
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        *width = fmt.fmt.pix.width;
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        *height = fmt.fmt.pix.height;
167
    }
168

    
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    return res;
170
}
171

    
172
static int first_field(int fd)
173
{
174
    int res;
175
    v4l2_std_id std;
176

    
177
    res = ioctl(fd, VIDIOC_G_STD, &std);
178
    if (res < 0) {
179
        return 0;
180
    }
181
    if (std & V4L2_STD_NTSC) {
182
        return 0;
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    }
184

    
185
    return 1;
186
}
187

    
188
static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt)
189
{
190
    int i;
191

    
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    for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
193
        if (fmt_conversion_table[i].ff_fmt == pix_fmt) {
194
            return fmt_conversion_table[i].v4l2_fmt;
195
        }
196
    }
197

    
198
    return 0;
199
}
200

    
201
static enum PixelFormat fmt_v4l2ff(uint32_t pix_fmt)
202
{
203
    int i;
204

    
205
    for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
206
        if (fmt_conversion_table[i].v4l2_fmt == pix_fmt) {
207
            return fmt_conversion_table[i].ff_fmt;
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        }
209
    }
210

    
211
    return -1;
212
}
213

    
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static int mmap_init(struct video_data *s)
215
{
216
    struct v4l2_requestbuffers req;
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    int i, res;
218

    
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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;
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    res = ioctl (s->fd, VIDIOC_REQBUFS, &req);
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    if (res < 0) {
225
        if (errno == EINVAL) {
226
            av_log(NULL, AV_LOG_ERROR, "Device does not support mmap\n");
227
        } else {
228
            av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
229
        }
230

    
231
        return -1;
232
    }
233

    
234
    if (req.count < 2) {
235
        av_log(NULL, AV_LOG_ERROR, "Insufficient buffer memory\n");
236

    
237
        return -1;
238
    }
239
    s->buffers = req.count;
240
    s->buf_start = av_malloc(sizeof(void *) * s->buffers);
241
    if (s->buf_start == NULL) {
242
        av_log(NULL, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
243

    
244
        return -1;
245
    }
246
    s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
247
    if (s->buf_len == NULL) {
248
        av_log(NULL, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
249
        av_free(s->buf_start);
250

    
251
        return -1;
252
    }
253

    
254
    for (i = 0; i < req.count; i++) {
255
        struct v4l2_buffer buf;
256

    
257
        memset(&buf, 0, sizeof(struct v4l2_buffer));
258
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
259
        buf.memory = V4L2_MEMORY_MMAP;
260
        buf.index = i;
261
        res = ioctl (s->fd, VIDIOC_QUERYBUF, &buf);
262
        if (res < 0) {
263
            av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
264

    
265
            return -1;
266
        }
267

    
268
        s->buf_len[i] = buf.length;
269
        if (s->buf_len[i] < s->frame_size) {
270
            av_log(NULL, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
271

    
272
            return -1;
273
        }
274
        s->buf_start[i] = mmap (NULL, buf.length,
275
                        PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
276
        if (s->buf_start[i] == MAP_FAILED) {
277
            av_log(NULL, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
278

    
279
            return -1;
280
        }
281
    }
282

    
283
    return 0;
284
}
285

    
286
static int read_init(struct video_data *s)
287
{
288
    return -1;
289
}
290

    
291
static int mmap_read_frame(struct video_data *s, void *frame, int64_t *ts)
292
{
293
    struct v4l2_buffer buf;
294
    int res;
295

    
296
    memset(&buf, 0, sizeof(struct v4l2_buffer));
297
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
298
    buf.memory = V4L2_MEMORY_MMAP;
299

    
300
    /* FIXME: Some special treatment might be needed in case of loss of signal... */
301
    while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 &&
302
           ((errno == EAGAIN) || (errno == EINTR)));
303
    if (res < 0) {
304
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
305

    
306
        return -1;
307
    }
308
    assert (buf.index < s->buffers);
309
    assert(buf.bytesused == s->frame_size);
310
    /* Image is at s->buff_start[buf.index] */
311
    memcpy(frame, s->buf_start[buf.index], buf.bytesused);
312
    *ts = buf.timestamp.tv_sec * int64_t_C(1000000) + buf.timestamp.tv_usec;
313

    
314
    res = ioctl (s->fd, VIDIOC_QBUF, &buf);
315
    if (res < 0) {
316
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
317

    
318
        return -1;
319
    }
320

    
321
    return s->buf_len[buf.index];
322
}
323

    
324
static int read_frame(struct video_data *s, void *frame, int64_t *ts)
325
{
326
    return -1;
327
}
328

    
329
static int mmap_start(struct video_data *s)
330
{
331
    enum v4l2_buf_type type;
332
    int i, res;
333

    
334
    for (i = 0; i < s->buffers; i++) {
335
        struct v4l2_buffer buf;
336

    
337
        memset(&buf, 0, sizeof(struct v4l2_buffer));
338
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
339
        buf.memory = V4L2_MEMORY_MMAP;
340
        buf.index  = i;
341

    
342
        res = ioctl (s->fd, VIDIOC_QBUF, &buf);
343
        if (res < 0) {
344
            av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
345

    
346
            return -1;
347
        }
348
    }
349

    
350
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
351
    res = ioctl (s->fd, VIDIOC_STREAMON, &type);
352
    if (res < 0) {
353
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
354

    
355
        return -1;
356
    }
357

    
358
    return 0;
359
}
360

    
361
static void mmap_close(struct video_data *s)
362
{
363
    enum v4l2_buf_type type;
364
    int i;
365

    
366
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
367
    /* We do not check for the result, because we could
368
     * not do anything about it anyway...
369
     */
370
    ioctl(s->fd, VIDIOC_STREAMOFF, &type);
371
    for (i = 0; i < s->buffers; i++) {
372
        munmap(s->buf_start[i], s->buf_len[i]);
373
    }
374
    av_free(s->buf_start);
375
    av_free(s->buf_len);
376
}
377

    
378
static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
379
{
380
    struct video_data *s = s1->priv_data;
381
    AVStream *st;
382
    int width, height;
383
    int res, frame_rate, frame_rate_base;
384
    uint32_t desired_format, capabilities;
385
    const char *video_device;
386

    
387
    if (ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
388
        av_log(s1, AV_LOG_ERROR, "Missing/Wrong parameters\n");
389

    
390
        return -1;
391
    }
392

    
393
    width = ap->width;
394
    height = ap->height;
395
    frame_rate = ap->time_base.den;
396
    frame_rate_base = ap->time_base.num;
397

    
398
    if((unsigned)width > 32767 || (unsigned)height > 32767) {
399
        av_log(s1, AV_LOG_ERROR, "Wrong size %dx%d\n", width, height);
400

    
401
        return -1;
402
    }
403

    
404
    st = av_new_stream(s1, 0);
405
    if (!st) {
406
        return -ENOMEM;
407
    }
408
    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
409

    
410
    s->width = width;
411
    s->height = height;
412
    s->frame_rate      = frame_rate;
413
    s->frame_rate_base = frame_rate_base;
414

    
415
    video_device = ap->device;
416
    if (!video_device) {
417
        video_device = "/dev/video";
418
    }
419
    capabilities = 0;
420
    s->fd = device_open(video_device, &capabilities);
421
    if (s->fd < 0) {
422
        av_free(st);
423

    
424
        return AVERROR_IO;
425
    }
426
    av_log(s1, AV_LOG_ERROR, "[%d]Capabilities: %x\n", s->fd, capabilities);
427

    
428
    desired_format = fmt_ff2v4l(ap->pix_fmt);
429
    if (desired_format == 0 || (device_init(s->fd, &width, &height, desired_format) < 0)) {
430
        int i, done;
431

    
432
        done = 0; i = 0;
433
        while (!done) {
434
            desired_format = fmt_conversion_table[i].v4l2_fmt;
435
            if (device_init(s->fd, &width, &height, desired_format) < 0) {
436
                desired_format = 0;
437
                i++;
438
            } else {
439
               done = 1;
440
            }
441
            if (i == sizeof(fmt_conversion_table) / sizeof(struct fmt_map)) {
442
               done = 1;
443
            }
444
        }
445
    }
446
    if (desired_format == 0) {
447
        av_log(s1, AV_LOG_ERROR, "Cannot find a proper format.\n");
448
        close(s->fd);
449
        av_free(st);
450

    
451
        return AVERROR_IO;
452
    }
453
    s->frame_format = desired_format;
454

    
455
    st->codec->pix_fmt = fmt_v4l2ff(desired_format);
456
    s->frame_size = avpicture_get_size(st->codec->pix_fmt, width, height);
457
    if (capabilities & V4L2_CAP_STREAMING) {
458
        s->io_method = io_mmap;
459
        res = mmap_init(s);
460
        res = mmap_start(s);
461
    } else {
462
        s->io_method = io_read;
463
        res = read_init(s);
464
    }
465
    if (res < 0) {
466
        close(s->fd);
467
        av_free(st);
468

    
469
        return AVERROR_IO;
470
    }
471
    s->top_field_first = first_field(s->fd);
472

    
473
    st->codec->codec_type = CODEC_TYPE_VIDEO;
474
    st->codec->codec_id = CODEC_ID_RAWVIDEO;
475
    st->codec->width = width;
476
    st->codec->height = height;
477
    st->codec->time_base.den = frame_rate;
478
    st->codec->time_base.num = frame_rate_base;
479
    st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
480

    
481
    return 0;
482
}
483

    
484
static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
485
{
486
    struct video_data *s = s1->priv_data;
487
    int res;
488

    
489
    if (av_new_packet(pkt, s->frame_size) < 0)
490
        return AVERROR_IO;
491

    
492
    if (s->io_method == io_mmap) {
493
        res = mmap_read_frame(s, pkt->data, &pkt->pts);
494
    } else if (s->io_method == io_read) {
495
        res = read_frame(s, pkt->data, &pkt->pts);
496
    } else {
497
        return AVERROR_IO;
498
    }
499
    if (res < 0) {
500
        return AVERROR_IO;
501
    }
502

    
503
    if (s1->streams[0]->codec->coded_frame) {
504
        s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
505
        s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
506
    }
507

    
508
    return s->frame_size;
509
}
510

    
511
static int v4l2_read_close(AVFormatContext *s1)
512
{
513
    struct video_data *s = s1->priv_data;
514

    
515
    if (s->io_method == io_mmap) {
516
        mmap_close(s);
517
    }
518

    
519
    close(s->fd);
520
    return 0;
521
}
522

    
523
static AVInputFormat v4l2_format = {
524
    "video4linux2",
525
    "video grab",
526
    sizeof(struct video_data),
527
    NULL,
528
    v4l2_read_header,
529
    v4l2_read_packet,
530
    v4l2_read_close,
531
    .flags = AVFMT_NOFILE,
532
};
533

    
534
int v4l2_init(void)
535
{
536
    av_register_input_format(&v4l2_format);
537
    return 0;
538
}