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FFmpeg/libavdevice/v4l2.c

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/*
* 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 AV_PIX_FMT_*
*
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; 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 "libavformat/internal.h"
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <poll.h>
#if HAVE_SYS_VIDEOIO_H
#include <sys/videoio.h>
#else
#include <linux/videodev2.h>
#endif
#include "libavutil/atomic.h"
#include "libavutil/avassert.h"
#include "libavutil/imgutils.h"
#include "libavutil/internal.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"
#include "libavutil/avstring.h"
#include "libavutil/mathematics.h"
static const int desired_video_buffers = 256;
#define V4L_ALLFORMATS 3
#define V4L_RAWFORMATS 1
#define V4L_COMPFORMATS 2
struct video_data {
AVClass *class;
int fd;
int frame_format; /* V4L2_PIX_FMT_* */
int width, height;
int frame_size;
int timeout;
int interlaced;
int top_field_first;
int buffers;
volatile int buffers_queued;
void **buf_start;
unsigned int *buf_len;
char *standard;
int channel;
char *video_size; /**< String describing video size,
set by a private option. */
char *pixel_format; /**< Set by a private option. */
int list_format; /**< Set by a private option. */
char *framerate; /**< Set by a private option. */
};
struct buff_data {
struct video_data *s;
int index;
int fd;
};
struct fmt_map {
enum AVPixelFormat ff_fmt;
enum AVCodecID codec_id;
uint32_t v4l2_fmt;
};
static struct fmt_map fmt_conversion_table[] = {
//ff_fmt codec_id v4l2_fmt
{ AV_PIX_FMT_YUV420P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420 },
{ AV_PIX_FMT_YUV422P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P },
{ AV_PIX_FMT_YUYV422, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUYV },
{ AV_PIX_FMT_UYVY422, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_UYVY },
{ AV_PIX_FMT_YUV411P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV411P },
{ AV_PIX_FMT_YUV410P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV410 },
{ AV_PIX_FMT_RGB555, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555 },
{ AV_PIX_FMT_RGB565, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565 },
{ AV_PIX_FMT_BGR24, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR24 },
{ AV_PIX_FMT_RGB24, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB24 },
{ AV_PIX_FMT_BGRA, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR32 },
{ AV_PIX_FMT_GRAY8, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_GREY },
{ AV_PIX_FMT_NV12, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12 },
{ AV_PIX_FMT_NONE, AV_CODEC_ID_MJPEG, V4L2_PIX_FMT_MJPEG },
{ AV_PIX_FMT_NONE, AV_CODEC_ID_MJPEG, V4L2_PIX_FMT_JPEG },
};
static int device_open(AVFormatContext *ctx)
{
struct v4l2_capability cap;
int fd;
int res, err;
int flags = O_RDWR;
char errbuf[128];
if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
flags |= O_NONBLOCK;
}
fd = avpriv_open(ctx->filename, flags);
if (fd < 0) {
err = AVERROR(errno);
av_strerror(err, errbuf, sizeof(errbuf));
av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
ctx->filename, errbuf);
return err;
}
res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
if (res < 0) {
err = AVERROR(errno);
av_strerror(err, errbuf, sizeof(errbuf));
av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
errbuf);
goto fail;
}
av_log(ctx, AV_LOG_VERBOSE, "[%d]Capabilities: %x\n",
fd, cap.capabilities);
if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
err = AVERROR(ENODEV);
goto fail;
}
if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
av_log(ctx, AV_LOG_ERROR,
"The device does not support the streaming I/O method.\n");
err = AVERROR(ENOSYS);
goto fail;
}
return fd;
fail:
close(fd);
return err;
}
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 = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
struct v4l2_pix_format *pix = &fmt.fmt.pix;
int res;
pix->width = *width;
pix->height = *height;
pix->pixelformat = pix_fmt;
pix->field = V4L2_FIELD_ANY;
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;
}
if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
av_log(ctx, AV_LOG_DEBUG, "The V4L2 driver using the interlaced mode");
s->interlaced = 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 AVPixelFormat pix_fmt, enum AVCodecID codec_id)
{
int i;
for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
if ((codec_id == AV_CODEC_ID_NONE ||
fmt_conversion_table[i].codec_id == codec_id) &&
(pix_fmt == AV_PIX_FMT_NONE ||
fmt_conversion_table[i].ff_fmt == pix_fmt)) {
return fmt_conversion_table[i].v4l2_fmt;
}
}
return 0;
}
static enum AVPixelFormat fmt_v4l2ff(uint32_t v4l2_fmt, enum AVCodecID 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 AV_PIX_FMT_NONE;
}
static enum AVCodecID 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 AV_CODEC_ID_NONE;
}
#if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
static void list_framesizes(AVFormatContext *ctx, int fd, uint32_t pixelformat)
{
struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
while(!ioctl(fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
switch (vfse.type) {
case V4L2_FRMSIZE_TYPE_DISCRETE:
av_log(ctx, AV_LOG_INFO, " %ux%u",
vfse.discrete.width, vfse.discrete.height);
break;
case V4L2_FRMSIZE_TYPE_CONTINUOUS:
case V4L2_FRMSIZE_TYPE_STEPWISE:
av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
vfse.stepwise.min_width,
vfse.stepwise.max_width,
vfse.stepwise.step_width,
vfse.stepwise.min_height,
vfse.stepwise.max_height,
vfse.stepwise.step_height);
}
vfse.index++;
}
}
#endif
static void list_formats(AVFormatContext *ctx, int fd, int type)
{
struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
while(!ioctl(fd, VIDIOC_ENUM_FMT, &vfd)) {
enum AVCodecID codec_id = fmt_v4l2codec(vfd.pixelformat);
enum AVPixelFormat pix_fmt = fmt_v4l2ff(vfd.pixelformat, codec_id);
vfd.index++;
if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
type & V4L_RAWFORMATS) {
const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
av_log(ctx, AV_LOG_INFO, "R : %9s : %20s :",
fmt_name ? fmt_name : "Unsupported",
vfd.description);
} else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
type & V4L_COMPFORMATS) {
AVCodec *codec = avcodec_find_encoder(codec_id);
av_log(ctx, AV_LOG_INFO, "C : %9s : %20s :",
codec ? codec->name : "Unsupported",
vfd.description);
} else {
continue;
}
#ifdef V4L2_FMT_FLAG_EMULATED
if (vfd.flags & V4L2_FMT_FLAG_EMULATED) {
av_log(ctx, AV_LOG_WARNING, "%s", "Emulated");
continue;
}
#endif
#if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
list_framesizes(ctx, fd, vfd.pixelformat);
#endif
av_log(ctx, AV_LOG_INFO, "\n");
}
}
static int mmap_init(AVFormatContext *ctx)
{
int i, res;
struct video_data *s = ctx->priv_data;
struct v4l2_requestbuffers req = {
.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
.count = desired_video_buffers,
.memory = V4L2_MEMORY_MMAP
};
res = ioctl(s->fd, VIDIOC_REQBUFS, &req);
if (res < 0) {
res = AVERROR(errno);
if (res == AVERROR(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 res;
}
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) {
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) {
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 = {
.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
.index = i,
.memory = V4L2_MEMORY_MMAP
};
res = ioctl(s->fd, VIDIOC_QUERYBUF, &buf);
if (res < 0) {
res = AVERROR(errno);
av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
return res;
}
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) {
char errbuf[128];
res = AVERROR(errno);
av_strerror(res, errbuf, sizeof(errbuf));
av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", errbuf);
return res;
}
}
return 0;
}
#if FF_API_DESTRUCT_PACKET
static void dummy_release_buffer(AVPacket *pkt)
{
av_assert0(0);
}
#endif
static void mmap_release_buffer(void *opaque, uint8_t *data)
{
struct v4l2_buffer buf = { 0 };
int res, fd;
struct buff_data *buf_descriptor = opaque;
struct video_data *s = buf_descriptor->s;
char errbuf[128];
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_strerror(AVERROR(errno), errbuf, sizeof(errbuf));
av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
errbuf);
}
avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
}
static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
{
struct video_data *s = ctx->priv_data;
struct v4l2_buffer buf = {
.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
.memory = V4L2_MEMORY_MMAP
};
struct pollfd p = { .fd = s->fd, .events = POLLIN };
int res;
res = poll(&p, 1, s->timeout);
if (res < 0)
return AVERROR(errno);
if (!(p.revents & (POLLIN | POLLERR | POLLHUP)))
return AVERROR(EAGAIN);
/* 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) {
char errbuf[128];
if (errno == EAGAIN) {
pkt->size = 0;
return AVERROR(EAGAIN);
}
res = AVERROR(errno);
av_strerror(res, errbuf, sizeof(errbuf));
av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
errbuf);
return res;
}
if (buf.index >= s->buffers) {
av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
return AVERROR(EINVAL);
}
avpriv_atomic_int_add_and_fetch(&s->buffers_queued, -1);
// always keep at least one buffer queued
av_assert0(avpriv_atomic_int_get(&s->buffers_queued) >= 1);
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] */
if (avpriv_atomic_int_get(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
/* when we start getting low on queued buffers, fall back on copying data */
res = av_new_packet(pkt, buf.bytesused);
if (res < 0) {
av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
return res;
}
memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
res = ioctl(s->fd, VIDIOC_QBUF, &buf);
if (res < 0) {
res = AVERROR(errno);
av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
av_free_packet(pkt);
return res;
}
avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
} else {
struct buff_data *buf_descriptor;
pkt->data = s->buf_start[buf.index];
pkt->size = buf.bytesused;
#if FF_API_DESTRUCT_PACKET
FF_DISABLE_DEPRECATION_WARNINGS
pkt->destruct = dummy_release_buffer;
FF_ENABLE_DEPRECATION_WARNINGS
#endif
buf_descriptor = av_malloc(sizeof(struct buff_data));
if (!buf_descriptor) {
/* Something went wrong... Since av_malloc() failed, we cannot even
* allocate a buffer for memcpying 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;
buf_descriptor->s = s;
pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
buf_descriptor, 0);
if (!pkt->buf) {
av_freep(&buf_descriptor);
return AVERROR(ENOMEM);
}
}
pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
return s->buf_len[buf.index];
}
static int mmap_start(AVFormatContext *ctx)
{
struct video_data *s = ctx->priv_data;
enum v4l2_buf_type type;
int i, res, err;
char errbuf[128];
for (i = 0; i < s->buffers; i++) {
struct v4l2_buffer buf = {
.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
.index = i,
.memory = V4L2_MEMORY_MMAP
};
res = ioctl(s->fd, VIDIOC_QBUF, &buf);
if (res < 0) {
err = AVERROR(errno);
av_strerror(err, errbuf, sizeof(errbuf));
av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
errbuf);
return err;
}
}
s->buffers_queued = s->buffers;
type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
res = ioctl(s->fd, VIDIOC_STREAMON, &type);
if (res < 0) {
err = AVERROR(errno);
av_strerror(err, errbuf, sizeof(errbuf));
av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
errbuf);
return err;
}
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)
{
struct video_data *s = s1->priv_data;
struct v4l2_input input = { 0 };
struct v4l2_standard standard = { 0 };
struct v4l2_streamparm streamparm = { 0 };
struct v4l2_fract *tpf = &streamparm.parm.capture.timeperframe;
AVRational framerate_q = { 0 };
int i, ret;
streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (s->framerate &&
(ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
av_log(s1, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
s->framerate);
return ret;
}
/* set tv video input */
input.index = s->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",
s->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",
s->channel);
return AVERROR(EIO);
}
if (s->standard) {
av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
s->standard);
/* set tv 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",
s->standard);
return AVERROR(EIO);
}
if (!av_strcasecmp(standard.name, s->standard)) {
break;
}
}
av_log(s1, AV_LOG_DEBUG,
"The V4L2 driver set standard: %s, id: %"PRIu64"\n",
s->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",
s->standard);
return AVERROR(EIO);
}
}
if (framerate_q.num && framerate_q.den) {
av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
framerate_q.den, framerate_q.num);
tpf->numerator = framerate_q.den;
tpf->denominator = framerate_q.num;
if (ioctl(s->fd, VIDIOC_S_PARM, &streamparm) != 0) {
av_log(s1, AV_LOG_ERROR,
"ioctl set time per frame(%d/%d) failed\n",
framerate_q.den, framerate_q.num);
return AVERROR(EIO);
}
if (framerate_q.num != tpf->denominator ||
framerate_q.den != tpf->numerator) {
av_log(s1, AV_LOG_INFO,
"The driver changed the time per frame from "
"%d/%d to %d/%d\n",
framerate_q.den, framerate_q.num,
tpf->numerator, tpf->denominator);
}
} else {
if (ioctl(s->fd, VIDIOC_G_PARM, &streamparm) != 0) {
char errbuf[128];
ret = AVERROR(errno);
av_strerror(ret, errbuf, sizeof(errbuf));
av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n",
errbuf);
return ret;
}
}
s1->streams[0]->avg_frame_rate.num = tpf->denominator;
s1->streams[0]->avg_frame_rate.den = tpf->numerator;
s->timeout = 100 +
av_rescale_q(1, s1->streams[0]->avg_frame_rate,
(AVRational){1, 1000});
return 0;
}
static uint32_t device_try_init(AVFormatContext *s1,
enum AVPixelFormat pix_fmt,
int *width,
int *height,
enum AVCodecID *codec_id)
{
uint32_t desired_format = fmt_ff2v4l(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 == AV_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 != AV_CODEC_ID_NONE);
}
return desired_format;
}
static int v4l2_read_header(AVFormatContext *s1)
{
struct video_data *s = s1->priv_data;
AVStream *st;
int res = 0;
uint32_t desired_format;
enum AVCodecID codec_id;
enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
st = avformat_new_stream(s1, NULL);
if (!st)
return AVERROR(ENOMEM);
s->fd = device_open(s1);
if (s->fd < 0)
return s->fd;
if (s->list_format) {
list_formats(s1, s->fd, s->list_format);
return AVERROR_EXIT;
}
avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
if (s->video_size &&
(res = av_parse_video_size(&s->width, &s->height, s->video_size)) < 0) {
av_log(s1, AV_LOG_ERROR, "Could not parse video size '%s'.\n",
s->video_size);
return res;
}
if (s->pixel_format) {
AVCodec *codec = avcodec_find_decoder_by_name(s->pixel_format);
if (codec)
s1->video_codec_id = codec->id;
pix_fmt = av_get_pix_fmt(s->pixel_format);
if (pix_fmt == AV_PIX_FMT_NONE && !codec) {
av_log(s1, AV_LOG_ERROR, "No such input format: %s.\n",
s->pixel_format);
return AVERROR(EINVAL);
}
}
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) {
char errbuf[128];
res = AVERROR(errno);
av_strerror(res, errbuf, sizeof(errbuf));
av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
errbuf);
return res;
}
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, pix_fmt, &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, pix_fmt);
close(s->fd);
return AVERROR(EIO);
}
if ((res = av_image_check_size(s->width, s->height, 0, s1) < 0))
return res;
s->frame_format = desired_format;
if ((res = v4l2_set_parameters(s1) < 0))
return res;
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 ((res = mmap_init(s1)) ||
(res = mmap_start(s1)) < 0) {
close(s->fd);
return res;
}
s->top_field_first = first_field(s->fd);
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
st->codec->codec_id = codec_id;
if (codec_id == AV_CODEC_ID_RAWVIDEO)
st->codec->codec_tag =
avcodec_pix_fmt_to_codec_tag(st->codec->pix_fmt);
st->codec->width = s->width;
st->codec->height = s->height;
st->codec->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
return 0;
}
static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
{
struct video_data *s = s1->priv_data;
AVFrame *frame = s1->streams[0]->codec->coded_frame;
int res;
av_init_packet(pkt);
if ((res = mmap_read_frame(s1, pkt)) < 0) {
return res;
}
if (frame && s->interlaced) {
frame->interlaced_frame = 1;
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 (avpriv_atomic_int_get(&s->buffers_queued) != s->buffers)
av_log(s1, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
"close.\n");
mmap_close(s);
close(s->fd);
return 0;
}
#define OFFSET(x) offsetof(struct video_data, x)
#define DEC AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
{ "standard", "TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
{ "channel", "TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC },
{ "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
{ "pixel_format", "Preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
{ "input_format", "Preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
{ "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
{ "list_formats", "List available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC, "list_formats" },
{ "all", "Show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
{ "raw", "Show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
{ "compressed", "Show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
{ NULL },
};
static const AVClass v4l2_class = {
.class_name = "V4L2 indev",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVInputFormat ff_v4l2_demuxer = {
.name = "video4linux2",
.long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
.priv_data_size = sizeof(struct video_data),
.read_header = v4l2_read_header,
.read_packet = v4l2_read_packet,
.read_close = v4l2_read_close,
.flags = AVFMT_NOFILE,
.priv_class = &v4l2_class,
};