Import pjproject-2.0.1

1 files changed, 819 insertions, 0 deletions

diff --git a/pjmedia/src/pjmedia-videodev/v4l2_dev.c b/pjmedia/src/pjmedia-videodev/v4l2_dev.c
new file mode 100644
index 0000000..880d47b
--- /dev/null
+++ b/pjmedia/src/pjmedia-videodev/v4l2_dev.c
@@ -0,0 +1,819 @@
+/* $Id: v4l2_dev.c 3901 2011-12-07 10:43:28Z nanang $ */
+/*
+ * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include <pjmedia-videodev/videodev_imp.h>
+#include <pjmedia/errno.h>
+#include <pj/assert.h>
+#include <pj/errno.h>
+#include <pj/file_access.h>
+#include <pj/log.h>
+#include <pj/os.h>
+#include <pj/rand.h>
+
+#if PJMEDIA_VIDEO_DEV_HAS_V4L2
+
+#include <linux/videodev2.h>
+#include <libv4l2.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/mman.h>
+
+#define THIS_FILE		"v4l2_dev.c"
+#define DRIVER_NAME		"v4l2"
+#define V4L2_MAX_DEVS		4
+#define DEFAULT_WIDTH		640
+#define DEFAULT_HEIGHT		480
+#define DEFAULT_FPS		25
+#define DEFAULT_CLOCK_RATE	90000
+#define INVALID_FD		-1
+#define BUFFER_CNT		2
+#define MAX_IOCTL_RETRY		20
+
+
+/* mapping between pjmedia_fmt_id and v4l2 pixel format */
+typedef struct vid4lin_fmt_map
+{
+    pj_uint32_t pjmedia_fmt_id;
+    pj_uint32_t	v4l2_fmt_id;
+} vid4lin_fmt_map;
+
+/* I/O type being used */
+enum vid4lin_io_type
+{
+    IO_TYPE_NONE,
+    IO_TYPE_READ,
+    IO_TYPE_MMAP,
+    IO_TYPE_MMAP_USER
+};
+
+/* descriptor for each mmap-ed buffer */
+typedef struct vid4lin_buffer
+{
+    void   *start;
+    size_t  length;
+} vid4lin_buffer;
+
+/* v4l2 device info */
+typedef struct vid4lin_dev_info
+{
+    pjmedia_vid_dev_info	 info;
+    char			 dev_name[32];
+    struct v4l2_capability 	 v4l2_cap;
+} vid4lin_dev_info;
+
+/* v4l2 factory */
+typedef struct vid4lin_factory
+{
+    pjmedia_vid_dev_factory	 base;
+    pj_pool_t			*pool;
+    pj_pool_t			*dev_pool;
+    pj_pool_factory		*pf;
+
+    unsigned			 dev_count;
+    vid4lin_dev_info		*dev_info;
+} vid4lin_factory;
+
+/* Video stream. */
+typedef struct vid4lin_stream
+{
+    pjmedia_vid_dev_stream	 base;		/**< Base stream	*/
+    pjmedia_vid_dev_param	 param;		/**< Settings		*/
+    pj_pool_t           	*pool;		/**< Memory pool.	*/
+
+    int			 	 fd;		/**< Video fd.		*/
+    char			 name[64];	/**< Name for log	*/
+    enum vid4lin_io_type	 io_type;	/**< I/O method.	*/
+    unsigned			 buf_cnt;	/**< MMap buf cnt.  	*/
+    vid4lin_buffer		*buffers;	/**< MMap buffers.  	*/
+    pj_time_val			 start_time;	/**< Time when started	*/
+
+    pjmedia_vid_dev_cb       	 vid_cb;	/**< Stream callback  	*/
+    void                	*user_data;	/**< Application data 	*/
+} vid4lin_stream;
+
+/* Use this to convert between pjmedia_format_id and V4L2 fourcc */
+static vid4lin_fmt_map v4l2_fmt_maps[] =
+{
+    { PJMEDIA_FORMAT_RGB24,	V4L2_PIX_FMT_BGR24 },
+    { PJMEDIA_FORMAT_RGBA,	V4L2_PIX_FMT_BGR32 },
+    { PJMEDIA_FORMAT_RGB32,	V4L2_PIX_FMT_BGR32 },
+    { PJMEDIA_FORMAT_AYUV,	V4L2_PIX_FMT_YUV32 },
+    { PJMEDIA_FORMAT_YUY2,	V4L2_PIX_FMT_YUYV },
+    { PJMEDIA_FORMAT_UYVY,	V4L2_PIX_FMT_UYVY }
+};
+
+/* Prototypes */
+static pj_status_t vid4lin_factory_init(pjmedia_vid_dev_factory *f);
+static pj_status_t vid4lin_factory_destroy(pjmedia_vid_dev_factory *f);
+static pj_status_t vid4lin_factory_refresh(pjmedia_vid_dev_factory *f);
+static unsigned    vid4lin_factory_get_dev_count(pjmedia_vid_dev_factory *f);
+static pj_status_t vid4lin_factory_get_dev_info(pjmedia_vid_dev_factory *f,
+					        unsigned index,
+					        pjmedia_vid_dev_info *info);
+static pj_status_t vid4lin_factory_default_param(pj_pool_t *pool,
+                                                 pjmedia_vid_dev_factory *f,
+					         unsigned index,
+					         pjmedia_vid_dev_param *param);
+static pj_status_t vid4lin_factory_create_stream(pjmedia_vid_dev_factory *f,
+						 pjmedia_vid_dev_param *prm,
+					         const pjmedia_vid_dev_cb *cb,
+					         void *user_data,
+					         pjmedia_vid_dev_stream **p);
+
+static pj_status_t vid4lin_stream_get_param(pjmedia_vid_dev_stream *strm,
+					    pjmedia_vid_dev_param *param);
+static pj_status_t vid4lin_stream_get_cap(pjmedia_vid_dev_stream *strm,
+				          pjmedia_vid_dev_cap cap,
+				          void *value);
+static pj_status_t vid4lin_stream_set_cap(pjmedia_vid_dev_stream *strm,
+				          pjmedia_vid_dev_cap cap,
+				          const void *value);
+static pj_status_t vid4lin_stream_get_frame(pjmedia_vid_dev_stream *strm,
+                                            pjmedia_frame *frame);
+static pj_status_t vid4lin_stream_start(pjmedia_vid_dev_stream *strm);
+static pj_status_t vid4lin_stream_stop(pjmedia_vid_dev_stream *strm);
+static pj_status_t vid4lin_stream_destroy(pjmedia_vid_dev_stream *strm);
+
+/* Operations */
+static pjmedia_vid_dev_factory_op factory_op =
+{
+    &vid4lin_factory_init,
+    &vid4lin_factory_destroy,
+    &vid4lin_factory_get_dev_count,
+    &vid4lin_factory_get_dev_info,
+    &vid4lin_factory_default_param,
+    &vid4lin_factory_create_stream,
+    &vid4lin_factory_refresh
+};
+
+static pjmedia_vid_dev_stream_op stream_op =
+{
+    &vid4lin_stream_get_param,
+    &vid4lin_stream_get_cap,
+    &vid4lin_stream_set_cap,
+    &vid4lin_stream_start,
+    &vid4lin_stream_get_frame,
+    NULL,
+    &vid4lin_stream_stop,
+    &vid4lin_stream_destroy
+};
+
+
+/****************************************************************************
+ * Factory operations
+ */
+/*
+ * Factory creation function.
+ */
+pjmedia_vid_dev_factory* pjmedia_v4l2_factory(pj_pool_factory *pf)
+{
+    vid4lin_factory *f;
+    pj_pool_t *pool;
+
+    pool = pj_pool_create(pf, DRIVER_NAME, 512, 512, NULL);
+    f = PJ_POOL_ZALLOC_T(pool, vid4lin_factory);
+    f->pf = pf;
+    f->pool = pool;
+    f->base.op = &factory_op;
+
+    return &f->base;
+}
+
+/* util: ioctl that tries harder. */
+static pj_status_t xioctl(int fh, int request, void *arg)
+{
+    enum { RETRY = MAX_IOCTL_RETRY };
+    int r, c=0;
+
+    do {
+	r = v4l2_ioctl(fh, request, arg);
+    } while (r==-1 && c++<RETRY && ((errno==EINTR) || (errno==EAGAIN)));
+
+    return (r == -1) ? pj_get_os_error() : PJ_SUCCESS;
+}
+
+/* Scan V4L2 devices */
+static pj_status_t v4l2_scan_devs(vid4lin_factory *f)
+{
+    vid4lin_dev_info vdi[V4L2_MAX_DEVS];
+    char dev_name[32];
+    unsigned i, old_count;
+    pj_status_t status;
+
+    if (f->dev_pool) {
+        pj_pool_release(f->dev_pool);
+        f->dev_pool = NULL;
+    }
+
+    pj_bzero(vdi, sizeof(vdi));
+    old_count = f->dev_count;
+    f->dev_count = 0;
+    f->dev_pool = pj_pool_create(f->pf, DRIVER_NAME, 500, 500, NULL);
+
+    for (i=0; i<V4L2_MAX_DEVS && f->dev_count < V4L2_MAX_DEVS; ++i) {
+	int fd;
+	vid4lin_dev_info *pdi;
+	pj_uint32_t fmt_cap[8];
+	int j, fmt_cnt=0;
+
+	pdi = &vdi[f->dev_count];
+
+	snprintf(dev_name, sizeof(dev_name), "/dev/video%d", i);
+	if (!pj_file_exists(dev_name))
+	    continue;
+
+	fd = v4l2_open(dev_name, O_RDWR, 0);
+	if (fd == -1)
+	    continue;
+
+	status = xioctl(fd, VIDIOC_QUERYCAP, &pdi->v4l2_cap);
+	if (status != PJ_SUCCESS) {
+	    PJ_PERROR(4,(THIS_FILE, status, "Error querying %s", dev_name));
+	    v4l2_close(fd);
+	    continue;
+	}
+
+	if ((pdi->v4l2_cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
+	    v4l2_close(fd);
+	    continue;
+	}
+
+	PJ_LOG(5,(THIS_FILE, "Found capture device %s", pdi->v4l2_cap.card));
+	PJ_LOG(5,(THIS_FILE, "  Enumerating formats:"));
+	for (j=0; fmt_cnt<PJ_ARRAY_SIZE(fmt_cap); ++j) {
+	    struct v4l2_fmtdesc fdesc;
+	    unsigned k;
+
+	    pj_bzero(&fdesc, sizeof(fdesc));
+	    fdesc.index = j;
+	    fdesc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+
+	    status = xioctl(fd, VIDIOC_ENUM_FMT, &fdesc);
+	    if (status != PJ_SUCCESS)
+		break;
+
+	    for (k=0; k<PJ_ARRAY_SIZE(v4l2_fmt_maps); ++k) {
+		if (v4l2_fmt_maps[k].v4l2_fmt_id == fdesc.pixelformat) {
+		    fmt_cap[fmt_cnt++] = v4l2_fmt_maps[k].pjmedia_fmt_id;
+		    PJ_LOG(5,(THIS_FILE, "   Supported: %s",
+			      fdesc.description));
+		    break;
+		}
+	    }
+	    if (k==PJ_ARRAY_SIZE(v4l2_fmt_maps)) {
+		PJ_LOG(5,(THIS_FILE, "   Unsupported: %s", fdesc.description));
+	    }
+	}
+
+	v4l2_close(fd);
+
+	if (fmt_cnt==0) {
+	    PJ_LOG(5,(THIS_FILE, "    Found no common format"));
+	    continue;
+	}
+
+	strncpy(pdi->dev_name, dev_name, sizeof(pdi->dev_name));
+	pdi->dev_name[sizeof(pdi->dev_name)-1] = '\0';
+	strncpy(pdi->info.name, (char*)pdi->v4l2_cap.card,
+		sizeof(pdi->info.name));
+	pdi->info.name[sizeof(pdi->info.name)-1] = '\0';
+	strncpy(pdi->info.driver, DRIVER_NAME, sizeof(pdi->info.driver));
+	pdi->info.driver[sizeof(pdi->info.driver)-1] = '\0';
+	pdi->info.dir = PJMEDIA_DIR_CAPTURE;
+	pdi->info.has_callback = PJ_FALSE;
+	pdi->info.caps = PJMEDIA_VID_DEV_CAP_FORMAT;
+
+	pdi->info.fmt_cnt = fmt_cnt;
+	for (j=0; j<fmt_cnt; ++j) {
+	    pjmedia_format_init_video(&pdi->info.fmt[j],
+				      fmt_cap[j],
+				      DEFAULT_WIDTH,
+				      DEFAULT_HEIGHT,
+				      DEFAULT_FPS, 1);
+	}
+	if (j < fmt_cnt)
+	    continue;
+
+	f->dev_count++;
+    }
+
+    if (f->dev_count == 0)
+	return PJ_SUCCESS;
+
+    if (f->dev_count > old_count || f->dev_info == NULL) {
+	f->dev_info = (vid4lin_dev_info*)
+		      pj_pool_calloc(f->dev_pool,
+				     f->dev_count,
+				     sizeof(vid4lin_dev_info));
+    }
+    pj_memcpy(f->dev_info, vdi, f->dev_count * sizeof(vid4lin_dev_info));
+
+    return PJ_SUCCESS;
+}
+
+
+/* API: init factory */
+static pj_status_t vid4lin_factory_init(pjmedia_vid_dev_factory *f)
+{
+    return vid4lin_factory_refresh(f);
+}
+
+/* API: destroy factory */
+static pj_status_t vid4lin_factory_destroy(pjmedia_vid_dev_factory *f)
+{
+    vid4lin_factory *cf = (vid4lin_factory*)f;
+    pj_pool_t *pool = cf->pool;
+
+    if (cf->dev_pool)
+        pj_pool_release(cf->dev_pool);
+    if (cf->pool) {
+	cf->pool = NULL;
+	pj_pool_release(pool);
+    }
+
+    return PJ_SUCCESS;
+}
+
+/* API: refresh the list of devices */
+static pj_status_t vid4lin_factory_refresh(pjmedia_vid_dev_factory *f)
+{
+    vid4lin_factory *cf = (vid4lin_factory*)f;
+    pj_status_t status;
+
+    status = v4l2_scan_devs(cf);
+    if (status != PJ_SUCCESS)
+	return status;
+
+    PJ_LOG(4, (THIS_FILE, "Video4Linux2 has %d devices",
+	       cf->dev_count));
+
+    return PJ_SUCCESS;
+}
+
+/* API: get number of devices */
+static unsigned vid4lin_factory_get_dev_count(pjmedia_vid_dev_factory *f)
+{
+    vid4lin_factory *cf = (vid4lin_factory*)f;
+    return cf->dev_count;
+}
+
+/* API: get device info */
+static pj_status_t vid4lin_factory_get_dev_info(pjmedia_vid_dev_factory *f,
+					     unsigned index,
+					     pjmedia_vid_dev_info *info)
+{
+    vid4lin_factory *cf = (vid4lin_factory*)f;
+
+    PJ_ASSERT_RETURN(index < cf->dev_count, PJMEDIA_EVID_INVDEV);
+
+    pj_memcpy(info, &cf->dev_info[index].info, sizeof(*info));
+
+    return PJ_SUCCESS;
+}
+
+/* API: create default device parameter */
+static pj_status_t vid4lin_factory_default_param(pj_pool_t *pool,
+                                                 pjmedia_vid_dev_factory *f,
+                                                 unsigned index,
+                                                 pjmedia_vid_dev_param *param)
+{
+    vid4lin_factory *cf = (vid4lin_factory*)f;
+
+    PJ_ASSERT_RETURN(index < cf->dev_count, PJMEDIA_EVID_INVDEV);
+
+    pj_bzero(param, sizeof(*param));
+    param->dir = PJMEDIA_DIR_CAPTURE;
+    param->cap_id = index;
+    param->rend_id = PJMEDIA_VID_INVALID_DEV;
+    param->flags = PJMEDIA_VID_DEV_CAP_FORMAT;
+    param->clock_rate = DEFAULT_CLOCK_RATE;
+    pjmedia_format_copy(&param->fmt, &cf->dev_info[index].info.fmt[0]);
+
+    return PJ_SUCCESS;
+}
+
+static vid4lin_fmt_map* get_v4l2_format_info(pjmedia_format_id id)
+{
+    unsigned i;
+
+    for (i = 0; i < PJ_ARRAY_SIZE(v4l2_fmt_maps); i++) {
+        if (v4l2_fmt_maps[i].pjmedia_fmt_id == id)
+            return &v4l2_fmt_maps[i];
+    }
+
+    return NULL;
+}
+
+/* util: setup format */
+static pj_status_t vid4lin_stream_init_fmt(vid4lin_stream *stream,
+					const pjmedia_vid_dev_param *param,
+					pj_uint32_t pix_fmt)
+{
+    pjmedia_video_format_detail *vfd;
+    struct v4l2_format v4l2_fmt;
+    pj_status_t status;
+
+    vfd = pjmedia_format_get_video_format_detail(&param->fmt, PJ_TRUE);
+    if (vfd == NULL)
+	return PJMEDIA_EVID_BADFORMAT;
+
+    pj_bzero(&v4l2_fmt, sizeof(v4l2_fmt));
+    v4l2_fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+    v4l2_fmt.fmt.pix.width       = vfd->size.w;
+    v4l2_fmt.fmt.pix.height      = vfd->size.h;
+    v4l2_fmt.fmt.pix.pixelformat = pix_fmt;
+    v4l2_fmt.fmt.pix.field       = V4L2_FIELD_INTERLACED;
+    status = xioctl(stream->fd, VIDIOC_S_FMT, &v4l2_fmt);
+    if (status != PJ_SUCCESS)
+	return status;
+
+    if (v4l2_fmt.fmt.pix.pixelformat != pix_fmt) {
+	status = PJMEDIA_EVID_BADFORMAT;
+	return status;
+    }
+
+    if ((v4l2_fmt.fmt.pix.width != vfd->size.w) ||
+	(v4l2_fmt.fmt.pix.height != vfd->size.h))
+    {
+	/* Size has changed */
+	vfd->size.w = v4l2_fmt.fmt.pix.width;
+	vfd->size.h = v4l2_fmt.fmt.pix.height;
+    }
+
+    return PJ_SUCCESS;
+}
+
+/* Util: initiate v4l2 streaming via mmap */
+static pj_status_t vid4lin_stream_init_streaming(vid4lin_stream *stream)
+{
+    struct v4l2_requestbuffers req;
+    unsigned i;
+    pj_status_t status;
+
+    pj_bzero(&req, sizeof(req));
+    req.count = BUFFER_CNT;
+    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+    req.memory = V4L2_MEMORY_MMAP;
+    status = xioctl(stream->fd, VIDIOC_REQBUFS, &req);
+    if (status != PJ_SUCCESS)
+	return status;
+
+    stream->buffers = pj_pool_calloc(stream->pool, req.count,
+				     sizeof(*stream->buffers));
+    stream->buf_cnt = 0;
+
+    for (i = 0; i < req.count; ++i) {
+	struct v4l2_buffer buf;
+
+	pj_bzero(&buf, sizeof(buf));
+
+	buf.type        = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	buf.memory      = V4L2_MEMORY_MMAP;
+	buf.index       = i;
+
+	status = xioctl(stream->fd, VIDIOC_QUERYBUF, &buf);
+	if (status != PJ_SUCCESS)
+	    goto on_error;
+
+	stream->buffers[i].length = buf.length;
+	stream->buffers[i].start = v4l2_mmap(NULL, buf.length,
+					     PROT_READ | PROT_WRITE,
+					     MAP_SHARED, stream->fd,
+					     buf.m.offset);
+
+	if (MAP_FAILED == stream->buffers[i].start) {
+	    status = pj_get_os_error();
+	    goto on_error;
+	}
+
+	stream->buf_cnt++;
+    }
+
+    PJ_LOG(5,(THIS_FILE, "  mmap streaming initialized"));
+
+    stream->io_type = IO_TYPE_MMAP;
+    return PJ_SUCCESS;
+
+on_error:
+    return status;
+}
+
+/* init streaming with user pointer */
+static pj_status_t vid4lin_stream_init_streaming_user(vid4lin_stream *stream)
+{
+    return PJ_ENOTSUP;
+}
+
+/* init streaming with read() */
+static pj_status_t vid4lin_stream_init_read_write(vid4lin_stream *stream)
+{
+    return PJ_ENOTSUP;
+}
+
+/* API: create stream */
+static pj_status_t vid4lin_factory_create_stream(pjmedia_vid_dev_factory *f,
+				      pjmedia_vid_dev_param *param,
+				      const pjmedia_vid_dev_cb *cb,
+				      void *user_data,
+				      pjmedia_vid_dev_stream **p_vid_strm)
+{
+    vid4lin_factory *cf = (vid4lin_factory*)f;
+    pj_pool_t *pool;
+    vid4lin_stream *stream;
+    vid4lin_dev_info *vdi;
+    const vid4lin_fmt_map *fmt_map;
+    const pjmedia_video_format_info *fmt_info;
+    pjmedia_video_format_detail *vfd;
+    pj_status_t status = PJ_SUCCESS;
+
+
+    PJ_ASSERT_RETURN(f && param && p_vid_strm, PJ_EINVAL);
+    PJ_ASSERT_RETURN(param->fmt.type == PJMEDIA_TYPE_VIDEO &&
+		     param->fmt.detail_type == PJMEDIA_FORMAT_DETAIL_VIDEO &&
+                     param->dir == PJMEDIA_DIR_CAPTURE,
+		     PJ_EINVAL);
+    PJ_ASSERT_RETURN(param->cap_id >= 0 && param->cap_id < cf->dev_count,
+		     PJMEDIA_EVID_INVDEV);
+
+    fmt_info = pjmedia_get_video_format_info(NULL, param->fmt.id);
+    if (!fmt_info || (fmt_map=get_v4l2_format_info(param->fmt.id))==NULL)
+        return PJMEDIA_EVID_BADFORMAT;
+
+    vdi = &cf->dev_info[param->cap_id];
+    vfd = pjmedia_format_get_video_format_detail(&param->fmt, PJ_TRUE);
+
+    /* Create and Initialize stream descriptor */
+    pool = pj_pool_create(cf->pf, vdi->info.name, 512, 512, NULL);
+    PJ_ASSERT_RETURN(pool != NULL, PJ_ENOMEM);
+
+    stream = PJ_POOL_ZALLOC_T(pool, vid4lin_stream);
+    pj_memcpy(&stream->param, param, sizeof(*param));
+    stream->pool = pool;
+    pj_memcpy(&stream->vid_cb, cb, sizeof(*cb));
+    strncpy(stream->name, vdi->info.name, sizeof(stream->name));
+    stream->name[sizeof(stream->name)-1] = '\0';
+    stream->user_data = user_data;
+    stream->fd = INVALID_FD;
+
+    stream->fd = v4l2_open(vdi->dev_name, O_RDWR, 0);
+    if (stream->fd < 0)
+	goto on_error;
+
+    status = vid4lin_stream_init_fmt(stream, param, fmt_map->v4l2_fmt_id);
+    if (status != PJ_SUCCESS)
+	goto on_error;
+
+    if (vdi->v4l2_cap.capabilities & V4L2_CAP_STREAMING)
+	status = vid4lin_stream_init_streaming(stream);
+
+    if (status!=PJ_SUCCESS && vdi->v4l2_cap.capabilities & V4L2_CAP_STREAMING)
+	status = vid4lin_stream_init_streaming_user(stream);
+
+    if (status!=PJ_SUCCESS && vdi->v4l2_cap.capabilities & V4L2_CAP_READWRITE)
+	status = vid4lin_stream_init_read_write(stream);
+
+    if (status != PJ_SUCCESS) {
+	PJ_LOG(1,(THIS_FILE, "Error: unable to initiate I/O on %s",
+		  stream->name));
+	goto on_error;
+    }
+
+    /* Done */
+    stream->base.op = &stream_op;
+    *p_vid_strm = &stream->base;
+
+    return PJ_SUCCESS;
+
+on_error:
+    if (status == PJ_SUCCESS)
+	status = PJ_RETURN_OS_ERROR(errno);
+
+    vid4lin_stream_destroy(&stream->base);
+    return status;
+}
+
+/* API: Get stream info. */
+static pj_status_t vid4lin_stream_get_param(pjmedia_vid_dev_stream *s,
+					    pjmedia_vid_dev_param *pi)
+{
+    vid4lin_stream *strm = (vid4lin_stream*)s;
+
+    PJ_ASSERT_RETURN(strm && pi, PJ_EINVAL);
+
+    pj_memcpy(pi, &strm->param, sizeof(*pi));
+
+    return PJ_SUCCESS;
+}
+
+/* API: get capability */
+static pj_status_t vid4lin_stream_get_cap(pjmedia_vid_dev_stream *s,
+                                          pjmedia_vid_dev_cap cap,
+                                          void *pval)
+{
+    vid4lin_stream *strm = (vid4lin_stream*)s;
+
+    PJ_UNUSED_ARG(strm);
+
+    PJ_ASSERT_RETURN(s && pval, PJ_EINVAL);
+
+    if (cap==PJMEDIA_VID_DEV_CAP_INPUT_SCALE)
+    {
+        return PJMEDIA_EVID_INVCAP;
+//	return PJ_SUCCESS;
+    } else {
+	return PJMEDIA_EVID_INVCAP;
+    }
+}
+
+/* API: set capability */
+static pj_status_t vid4lin_stream_set_cap(pjmedia_vid_dev_stream *s,
+                                          pjmedia_vid_dev_cap cap,
+                                          const void *pval)
+{
+    vid4lin_stream *strm = (vid4lin_stream*)s;
+
+
+    PJ_ASSERT_RETURN(s && pval, PJ_EINVAL);
+
+    /*
+    if (cap==PJMEDIA_VID_DEV_CAP_INPUT_SCALE)
+    {
+	return PJ_SUCCESS;
+    }
+    */
+    PJ_UNUSED_ARG(strm);
+    PJ_UNUSED_ARG(cap);
+    PJ_UNUSED_ARG(pval);
+
+    return PJMEDIA_EVID_INVCAP;
+}
+
+/* get frame from mmap */
+static pj_status_t vid4lin_stream_get_frame_mmap(vid4lin_stream *stream,
+                                                 pjmedia_frame *frame)
+{
+    struct v4l2_buffer buf;
+    pj_time_val time;
+    pj_status_t status = PJ_SUCCESS;
+
+    pj_bzero(&buf, sizeof(buf));
+    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+    buf.memory = V4L2_MEMORY_MMAP;
+    status = xioctl(stream->fd, VIDIOC_DQBUF, &buf);
+    if (status != PJ_SUCCESS)
+	return status;
+
+    if (frame->size < buf.bytesused) {
+	/* supplied buffer is too small */
+	pj_assert(!"frame buffer is too small for v4l2");
+	status = PJ_ETOOSMALL;
+	goto on_return;
+    }
+
+    time.sec = buf.timestamp.tv_sec;
+    time.msec = buf.timestamp.tv_usec / 1000;
+    PJ_TIME_VAL_SUB(time, stream->start_time);
+
+    frame->type = PJMEDIA_FRAME_TYPE_VIDEO;
+    frame->bit_info = 0;
+    frame->size = buf.bytesused;
+    frame->timestamp.u64 = PJ_UINT64(1) * PJ_TIME_VAL_MSEC(time) *
+			   stream->param.clock_rate / PJ_UINT64(1000);
+    pj_memcpy(frame->buf, stream->buffers[buf.index].start, buf.bytesused);
+
+on_return:
+    pj_bzero(&buf, sizeof(buf));
+    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+    buf.memory = V4L2_MEMORY_MMAP;
+    xioctl(stream->fd, VIDIOC_QBUF, &buf);
+
+    return status;
+}
+
+/* API: Get frame from stream */
+static pj_status_t vid4lin_stream_get_frame(pjmedia_vid_dev_stream *strm,
+                                            pjmedia_frame *frame)
+{
+    vid4lin_stream *stream = (vid4lin_stream*)strm;
+
+    if (stream->io_type == IO_TYPE_MMAP)
+	return vid4lin_stream_get_frame_mmap(stream, frame);
+    else {
+	pj_assert(!"Unsupported i/o type");
+	return PJ_EINVALIDOP;
+    }
+}
+
+/* API: Start stream. */
+static pj_status_t vid4lin_stream_start(pjmedia_vid_dev_stream *strm)
+{
+    vid4lin_stream *stream = (vid4lin_stream*)strm;
+    struct v4l2_buffer buf;
+    enum v4l2_buf_type type;
+    unsigned i;
+    pj_status_t status;
+
+    PJ_ASSERT_RETURN(stream->fd != -1, PJ_EINVALIDOP);
+
+    PJ_LOG(4, (THIS_FILE, "Starting v4l2 video stream %s", stream->name));
+
+    pj_gettimeofday(&stream->start_time);
+
+    for (i = 0; i < stream->buf_cnt; ++i) {
+	pj_bzero(&buf, sizeof(buf));
+	buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	buf.memory = V4L2_MEMORY_MMAP;
+	buf.index = i;
+	status = xioctl(stream->fd, VIDIOC_QBUF, &buf);
+	if (status != PJ_SUCCESS)
+	    goto on_error;
+    }
+    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+
+    status = xioctl(stream->fd, VIDIOC_STREAMON, &type);
+    if (status != PJ_SUCCESS)
+	goto on_error;
+
+    return PJ_SUCCESS;
+
+on_error:
+    if (i > 0) {
+	/* Dequeue already enqueued buffers. Can we do this while streaming
+	 * is not started?
+	 */
+	unsigned n = i;
+	for (i=0; i<n; ++i) {
+	    pj_bzero(&buf, sizeof(buf));
+	    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	    buf.memory = V4L2_MEMORY_MMAP;
+	    xioctl(stream->fd, VIDIOC_DQBUF, &buf);
+	}
+    }
+    return status;
+}
+
+/* API: Stop stream. */
+static pj_status_t vid4lin_stream_stop(pjmedia_vid_dev_stream *strm)
+{
+    vid4lin_stream *stream = (vid4lin_stream*)strm;
+    enum v4l2_buf_type type;
+    pj_status_t status;
+
+    if (stream->fd < 0)
+	return PJ_SUCCESS;
+
+    PJ_LOG(4, (THIS_FILE, "Stopping v4l2 video stream %s", stream->name));
+
+    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+    status = xioctl(stream->fd, VIDIOC_STREAMOFF, &type);
+    if (status != PJ_SUCCESS)
+	return status;
+
+    return PJ_SUCCESS;
+}
+
+
+/* API: Destroy stream. */
+static pj_status_t vid4lin_stream_destroy(pjmedia_vid_dev_stream *strm)
+{
+    vid4lin_stream *stream = (vid4lin_stream*)strm;
+    unsigned i;
+
+    PJ_ASSERT_RETURN(stream != NULL, PJ_EINVAL);
+
+    vid4lin_stream_stop(strm);
+
+    PJ_LOG(4, (THIS_FILE, "Destroying v4l2 video stream %s", stream->name));
+
+    for (i=0; i<stream->buf_cnt; ++i) {
+	if (stream->buffers[i].start != MAP_FAILED) {
+	    v4l2_munmap(stream->buffers[i].start, stream->buffers[i].length);
+	    stream->buffers[i].start = MAP_FAILED;
+	}
+    }
+
+    if (stream->fd >= 0) {
+	v4l2_close(stream->fd);
+	stream->fd = -1;
+    }
+    pj_pool_release(stream->pool);
+
+    return PJ_SUCCESS;
+}
+
+#endif	/* PJMEDIA_VIDEO_DEV_HAS_V4L2 */