PeerStreamer

/*

 * Video4Linux2 grab interface

 * Copyright (c) 2000,2001 Fabrice Bellard

 * Copyright (c) 2006 Luca Abeni

 *

 * Part of this file is based on the V4L2 video capture example

 * (http://v4l2spec.bytesex.org/v4l2spec/capture.c)

 *

 * Thanks to Michael Niedermayer for providing the mapping between

 * V4L2_PIX_FMT_* and PIX_FMT_*

 *

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#undef __STRICT_ANSI__ //workaround due to broken kernel headers

#include "config.h"

#include "libavformat/avformat.h"

#include <unistd.h>

#include <fcntl.h>

#include <sys/ioctl.h>

#include <sys/mman.h>

#include <sys/time.h>

#if HAVE_SYS_VIDEOIO_H

#include <sys/videoio.h>

#else

#include <asm/types.h>

#include <linux/videodev2.h>

#endif

#include <time.h>

#include <strings.h>

#include "libavutil/imgutils.h"

static const int desired_video_buffers = 256;

enum io_method {

    io_read,

    io_mmap,

    io_userptr

};

struct video_data {

    int fd;

    int frame_format; /* V4L2_PIX_FMT_* */

    enum io_method io_method;

    int width, height;

    int frame_size;

    int top_field_first;

    int buffers;

    void **buf_start;

    unsigned int *buf_len;

};

struct buff_data {

    int index;

    int fd;

};

struct fmt_map {

    enum PixelFormat ff_fmt;

    enum CodecID codec_id;

    uint32_t v4l2_fmt;

};

static struct fmt_map fmt_conversion_table[] = {

    //ff_fmt           codec_id           v4l2_fmt

    { PIX_FMT_YUV420P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420  },

    { PIX_FMT_YUV422P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P },

    { PIX_FMT_YUYV422, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUYV    },

    { PIX_FMT_UYVY422, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_UYVY    },

    { PIX_FMT_YUV411P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV411P },

    { PIX_FMT_YUV410P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV410  },

    { PIX_FMT_RGB555,  CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555  },

    { PIX_FMT_RGB565,  CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565  },

    { PIX_FMT_BGR24,   CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR24   },

    { PIX_FMT_RGB24,   CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB24   },

    { PIX_FMT_BGRA,    CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR32   },

    { PIX_FMT_GRAY8,   CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_GREY    },

    { PIX_FMT_NV12,    CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12    },

    { PIX_FMT_NONE,    CODEC_ID_MJPEG,    V4L2_PIX_FMT_MJPEG   },

    { PIX_FMT_NONE,    CODEC_ID_MJPEG,    V4L2_PIX_FMT_JPEG    },

};

static int device_open(AVFormatContext *ctx, uint32_t *capabilities)

{

    struct v4l2_capability cap;

    int fd;

    int res, err;

    int flags = O_RDWR;

    if (ctx->flags & AVFMT_FLAG_NONBLOCK) {

        flags |= O_NONBLOCK;

    }

    fd = open(ctx->filename, flags, 0);

    if (fd < 0) {

        av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",

                 ctx->filename, strerror(errno));

        return AVERROR(errno);

    }

    res = ioctl(fd, VIDIOC_QUERYCAP, &cap);

    // ENOIOCTLCMD definition only availble on __KERNEL__

    if (res < 0 && ((err = errno) == 515)) {

        av_log(ctx, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");

        close(fd);

        return AVERROR(515);

    }

    if (res < 0) {

        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",

                 strerror(errno));

        close(fd);

        return AVERROR(err);

    }

    if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {

        av_log(ctx, AV_LOG_ERROR, "Not a video capture device\n");

        close(fd);

        return AVERROR(ENODEV);

    }

    *capabilities = cap.capabilities;

    return fd;

}

static int device_init(AVFormatContext *ctx, int *width, int *height, uint32_t pix_fmt)

{

    struct video_data *s = ctx->priv_data;

    int fd = s->fd;

    struct v4l2_format fmt;

    int res;

    memset(&fmt, 0, sizeof(struct v4l2_format));

    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

    fmt.fmt.pix.width = *width;

    fmt.fmt.pix.height = *height;

    fmt.fmt.pix.pixelformat = pix_fmt;

    fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;

    res = ioctl(fd, VIDIOC_S_FMT, &fmt);

    if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {

        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);

        *width = fmt.fmt.pix.width;

        *height = fmt.fmt.pix.height;

    }

    if (pix_fmt != fmt.fmt.pix.pixelformat) {

        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);

        res = -1;

    }

    return res;

}

static int first_field(int fd)

{

    int res;

    v4l2_std_id std;

    res = ioctl(fd, VIDIOC_G_STD, &std);

    if (res < 0) {

        return 0;

    }

    if (std & V4L2_STD_NTSC) {

        return 0;

    }

    return 1;

}

static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt, enum CodecID codec_id)

{

    int i;

    for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {

        if ((codec_id == CODEC_ID_NONE ||

             fmt_conversion_table[i].codec_id == codec_id) &&

            (pix_fmt == PIX_FMT_NONE ||

             fmt_conversion_table[i].ff_fmt == pix_fmt)) {

            return fmt_conversion_table[i].v4l2_fmt;

        }

    }

    return 0;

}

static enum PixelFormat fmt_v4l2ff(uint32_t v4l2_fmt, enum CodecID codec_id)

{

    int i;

    for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {

        if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt &&

            fmt_conversion_table[i].codec_id == codec_id) {

            return fmt_conversion_table[i].ff_fmt;

        }

    }

    return PIX_FMT_NONE;

}

static enum CodecID fmt_v4l2codec(uint32_t v4l2_fmt)

{

    int i;

    for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {

        if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt) {

            return fmt_conversion_table[i].codec_id;

        }

    }

    return CODEC_ID_NONE;

}

static int mmap_init(AVFormatContext *ctx)

{

    struct video_data *s = ctx->priv_data;

    struct v4l2_requestbuffers req;

    int i, res;

    memset(&req, 0, sizeof(struct v4l2_requestbuffers));

    req.count = desired_video_buffers;

    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

    req.memory = V4L2_MEMORY_MMAP;

    res = ioctl(s->fd, VIDIOC_REQBUFS, &req);

    if (res < 0) {

        if (errno == EINVAL) {

            av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");

        } else {

            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");

        }

        return AVERROR(errno);

    }

    if (req.count < 2) {

        av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");

        return AVERROR(ENOMEM);

    }

    s->buffers = req.count;

    s->buf_start = av_malloc(sizeof(void *) * s->buffers);

    if (s->buf_start == NULL) {

        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");

        return AVERROR(ENOMEM);

    }

    s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);

    if (s->buf_len == NULL) {

        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");

        av_free(s->buf_start);

        return AVERROR(ENOMEM);

    }

    for (i = 0; i < req.count; i++) {

        struct v4l2_buffer buf;

        memset(&buf, 0, sizeof(struct v4l2_buffer));

        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

        buf.memory = V4L2_MEMORY_MMAP;

        buf.index = i;

        res = ioctl(s->fd, VIDIOC_QUERYBUF, &buf);

        if (res < 0) {

            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");

            return AVERROR(errno);

        }

        s->buf_len[i] = buf.length;

        if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {

            av_log(ctx, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);

            return -1;

        }

        s->buf_start[i] = mmap (NULL, buf.length,

                        PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);

        if (s->buf_start[i] == MAP_FAILED) {

            av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));

            return AVERROR(errno);

        }

    }

    return 0;

}

static int read_init(AVFormatContext *ctx)

{

    return -1;

}

static void mmap_release_buffer(AVPacket *pkt)

{

    struct v4l2_buffer buf;

    int res, fd;

    struct buff_data *buf_descriptor = pkt->priv;

    if (pkt->data == NULL) {

         return;

    }

    memset(&buf, 0, sizeof(struct v4l2_buffer));

    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

    buf.memory = V4L2_MEMORY_MMAP;

    buf.index = buf_descriptor->index;

    fd = buf_descriptor->fd;

    av_free(buf_descriptor);

    res = ioctl(fd, VIDIOC_QBUF, &buf);

    if (res < 0) {

        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));

    }

    pkt->data = NULL;

    pkt->size = 0;

}

static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)

{

    struct video_data *s = ctx->priv_data;

    struct v4l2_buffer buf;

    struct buff_data *buf_descriptor;

    int res;

    memset(&buf, 0, sizeof(struct v4l2_buffer));

    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

    buf.memory = V4L2_MEMORY_MMAP;

    /* FIXME: Some special treatment might be needed in case of loss of signal... */

    while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));

    if (res < 0) {

        if (errno == EAGAIN) {

            pkt->size = 0;

            return AVERROR(EAGAIN);

        }

        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));

        return AVERROR(errno);

    }

    assert (buf.index < s->buffers);

    if (s->frame_size > 0 && buf.bytesused != s->frame_size) {

        av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);

        return AVERROR_INVALIDDATA;

    }

    /* Image is at s->buff_start[buf.index] */

    pkt->data= s->buf_start[buf.index];

    pkt->size = buf.bytesused;

    pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;

    pkt->destruct = mmap_release_buffer;

    buf_descriptor = av_malloc(sizeof(struct buff_data));

    if (buf_descriptor == NULL) {

        /* Something went wrong... Since av_malloc() failed, we cannot even

         * allocate a buffer for memcopying into it

         */

        av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");

        res = ioctl(s->fd, VIDIOC_QBUF, &buf);

        return AVERROR(ENOMEM);

    }

    buf_descriptor->fd = s->fd;

    buf_descriptor->index = buf.index;

    pkt->priv = buf_descriptor;

    return s->buf_len[buf.index];

}

static int read_frame(AVFormatContext *ctx, AVPacket *pkt)

{

    return -1;

}

static int mmap_start(AVFormatContext *ctx)

{

    struct video_data *s = ctx->priv_data;

    enum v4l2_buf_type type;

    int i, res;

    for (i = 0; i < s->buffers; i++) {

        struct v4l2_buffer buf;

        memset(&buf, 0, sizeof(struct v4l2_buffer));

        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

        buf.memory = V4L2_MEMORY_MMAP;

        buf.index  = i;

        res = ioctl(s->fd, VIDIOC_QBUF, &buf);

        if (res < 0) {

            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));

            return AVERROR(errno);

        }

    }

    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

    res = ioctl(s->fd, VIDIOC_STREAMON, &type);

    if (res < 0) {

        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));

        return AVERROR(errno);

    }

    return 0;

}

static void mmap_close(struct video_data *s)

{

    enum v4l2_buf_type type;

    int i;

    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

    /* We do not check for the result, because we could

     * not do anything about it anyway...

     */

    ioctl(s->fd, VIDIOC_STREAMOFF, &type);

    for (i = 0; i < s->buffers; i++) {

        munmap(s->buf_start[i], s->buf_len[i]);

    }

    av_free(s->buf_start);

    av_free(s->buf_len);

}

static int v4l2_set_parameters(AVFormatContext *s1, AVFormatParameters *ap)

{

    struct video_data *s = s1->priv_data;

    struct v4l2_input input;

    struct v4l2_standard standard;

    struct v4l2_streamparm streamparm = { 0 };

    struct v4l2_fract *tpf = &streamparm.parm.capture.timeperframe;

    int i;

    streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

    if (ap->channel>=0) {

        /* set tv video input */

        memset (&input, 0, sizeof (input));

        input.index = ap->channel;

        if (ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {

            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");

            return AVERROR(EIO);

        }

        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",

               ap->channel, input.name);

        if (ioctl(s->fd, VIDIOC_S_INPUT, &input.index) < 0) {

            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set input(%d) failed\n",

                   ap->channel);

            return AVERROR(EIO);

        }

    }

    if (ap->standard) {

        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",

               ap->standard);

        /* set tv standard */

        memset (&standard, 0, sizeof (standard));

        for(i=0;;i++) {

            standard.index = i;

            if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {

                av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",

                       ap->standard);

                return AVERROR(EIO);

            }

            if (!strcasecmp(standard.name, ap->standard)) {

                break;

            }

        }

        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s, id: %"PRIu64"\n",

               ap->standard, (uint64_t)standard.id);

        if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {

            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",

                   ap->standard);

            return AVERROR(EIO);

        }

    }

    if (ap->time_base.num && ap->time_base.den) {

        av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",

               ap->time_base.num, ap->time_base.den);

        tpf->numerator = ap->time_base.num;

        tpf->denominator = ap->time_base.den;

        if (ioctl(s->fd, VIDIOC_S_PARM, &streamparm) != 0) {

            av_log(s1, AV_LOG_ERROR,

                   "ioctl set time per frame(%d/%d) failed\n",

                   ap->time_base.num, ap->time_base.den);

            return AVERROR(EIO);

        }

        if (ap->time_base.den != tpf->denominator ||

            ap->time_base.num != tpf->numerator) {

            av_log(s1, AV_LOG_INFO,

                   "The driver changed the time per frame from %d/%d to %d/%d\n",

                   ap->time_base.num, ap->time_base.den,

                   tpf->numerator, tpf->denominator);

        }

    } else {

        /* if timebase value is not set in ap, read the timebase value from the driver */

        if (ioctl(s->fd, VIDIOC_G_PARM, &streamparm) != 0) {

            av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n", strerror(errno));

            return AVERROR(errno);

        }

    }

    ap->time_base.num = tpf->numerator;

    ap->time_base.den = tpf->denominator;

    return 0;

}

static uint32_t device_try_init(AVFormatContext *s1,

                                const AVFormatParameters *ap,

                                int *width,

                                int *height,

                                enum CodecID *codec_id)

{

    uint32_t desired_format = fmt_ff2v4l(ap->pix_fmt, s1->video_codec_id);

    if (desired_format == 0 ||

        device_init(s1, width, height, desired_format) < 0) {

        int i;

        desired_format = 0;

        for (i = 0; i<FF_ARRAY_ELEMS(fmt_conversion_table); i++) {

            if (s1->video_codec_id == CODEC_ID_NONE ||

                fmt_conversion_table[i].codec_id == s1->video_codec_id) {

                desired_format = fmt_conversion_table[i].v4l2_fmt;

                if (device_init(s1, width, height, desired_format) >= 0) {

                    break;

                }

                desired_format = 0;

            }

        }

    }

    if (desired_format != 0) {

        *codec_id = fmt_v4l2codec(desired_format);

        assert(*codec_id != CODEC_ID_NONE);

    }

    return desired_format;

}

static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)

{

    struct video_data *s = s1->priv_data;

    AVStream *st;

    int res;

    uint32_t desired_format, capabilities;

    enum CodecID codec_id;

    st = av_new_stream(s1, 0);

    if (!st) {

        return AVERROR(ENOMEM);

    }

    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */

    s->width  = ap->width;

    s->height = ap->height;

    capabilities = 0;

    s->fd = device_open(s1, &capabilities);

    if (s->fd < 0) {

        return AVERROR(EIO);

    }

    av_log(s1, AV_LOG_VERBOSE, "[%d]Capabilities: %x\n", s->fd, capabilities);

    if (!s->width && !s->height) {

        struct v4l2_format fmt;

        av_log(s1, AV_LOG_VERBOSE, "Querying the device for the current frame size\n");

        fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

        if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {

            av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n", strerror(errno));

            return AVERROR(errno);

        }

        s->width  = fmt.fmt.pix.width;

        s->height = fmt.fmt.pix.height;

        av_log(s1, AV_LOG_VERBOSE, "Setting frame size to %dx%d\n", s->width, s->height);

    }

    desired_format = device_try_init(s1, ap, &s->width, &s->height, &codec_id);

    if (desired_format == 0) {

        av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for "

               "codec_id %d, pix_fmt %d.\n", s1->video_codec_id, ap->pix_fmt);

        close(s->fd);

        return AVERROR(EIO);

    }

    if (av_image_check_size(s->width, s->height, 0, s1) < 0)

        return AVERROR(EINVAL);

    s->frame_format = desired_format;

    if (v4l2_set_parameters(s1, ap) < 0)

        return AVERROR(EIO);

    st->codec->pix_fmt = fmt_v4l2ff(desired_format, codec_id);

    s->frame_size = avpicture_get_size(st->codec->pix_fmt, s->width, s->height);

    if (capabilities & V4L2_CAP_STREAMING) {

        s->io_method = io_mmap;

        res = mmap_init(s1);

        if (res == 0) {

            res = mmap_start(s1);

        }

    } else {

        s->io_method = io_read;

        res = read_init(s1);

    }

    if (res < 0) {

        close(s->fd);

        return AVERROR(EIO);

    }

    s->top_field_first = first_field(s->fd);

    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

    st->codec->codec_id = codec_id;

    st->codec->width = s->width;

    st->codec->height = s->height;

    st->codec->time_base.den = ap->time_base.den;

    st->codec->time_base.num = ap->time_base.num;

    st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;

    return 0;

}

static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)

{

    struct video_data *s = s1->priv_data;

    int res;

    if (s->io_method == io_mmap) {

        av_init_packet(pkt);

        res = mmap_read_frame(s1, pkt);

    } else if (s->io_method == io_read) {

        if (av_new_packet(pkt, s->frame_size) < 0)

            return AVERROR(EIO);

        res = read_frame(s1, pkt);

    } else {

        return AVERROR(EIO);

    }

    if (res < 0) {

        return res;

    }

    if (s1->streams[0]->codec->coded_frame) {

        s1->streams[0]->codec->coded_frame->interlaced_frame = 1;

        s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;

    }

    return pkt->size;

}

static int v4l2_read_close(AVFormatContext *s1)

{

    struct video_data *s = s1->priv_data;

    if (s->io_method == io_mmap) {

        mmap_close(s);

    }

    close(s->fd);

    return 0;

}

AVInputFormat ff_v4l2_demuxer = {

    "video4linux2",

    NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),

    sizeof(struct video_data),

    NULL,

    v4l2_read_header,

    v4l2_read_packet,

    v4l2_read_close,

    .flags = AVFMT_NOFILE,

};