summaryrefslogtreecommitdiff
path: root/drivers/media/platform/rockchip/rkcif/rkcif-stream.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/media/platform/rockchip/rkcif/rkcif-stream.c')
-rw-r--r--drivers/media/platform/rockchip/rkcif/rkcif-stream.c636
1 files changed, 636 insertions, 0 deletions
diff --git a/drivers/media/platform/rockchip/rkcif/rkcif-stream.c b/drivers/media/platform/rockchip/rkcif/rkcif-stream.c
new file mode 100644
index 000000000000..e00010a91e8b
--- /dev/null
+++ b/drivers/media/platform/rockchip/rkcif/rkcif-stream.c
@@ -0,0 +1,636 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Rockchip Camera Interface (CIF) Driver
+ *
+ * Copyright (C) 2025 Michael Riesch <michael.riesch@wolfvision.net>
+ * Copyright (C) 2025 Collabora, Ltd.
+ */
+
+#include <linux/pm_runtime.h>
+
+#include <media/v4l2-common.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-mc.h>
+#include <media/v4l2-subdev.h>
+#include <media/videobuf2-dma-contig.h>
+
+#include "rkcif-common.h"
+#include "rkcif-stream.h"
+
+#define CIF_REQ_BUFS_MIN 1
+#define CIF_MIN_WIDTH 64
+#define CIF_MIN_HEIGHT 64
+#define CIF_MAX_WIDTH 8192
+#define CIF_MAX_HEIGHT 8192
+
+static inline struct rkcif_buffer *to_rkcif_buffer(struct vb2_v4l2_buffer *vb)
+{
+ return container_of(vb, struct rkcif_buffer, vb);
+}
+
+static inline struct rkcif_stream *to_rkcif_stream(struct video_device *vdev)
+{
+ return container_of(vdev, struct rkcif_stream, vdev);
+}
+
+static struct rkcif_buffer *rkcif_stream_pop_buffer(struct rkcif_stream *stream)
+{
+ struct rkcif_buffer *buffer;
+
+ guard(spinlock_irqsave)(&stream->driver_queue_lock);
+
+ if (list_empty(&stream->driver_queue))
+ return NULL;
+
+ buffer = list_first_entry(&stream->driver_queue, struct rkcif_buffer,
+ queue);
+ list_del(&buffer->queue);
+
+ return buffer;
+}
+
+static void rkcif_stream_push_buffer(struct rkcif_stream *stream,
+ struct rkcif_buffer *buffer)
+{
+ guard(spinlock_irqsave)(&stream->driver_queue_lock);
+
+ list_add_tail(&buffer->queue, &stream->driver_queue);
+}
+
+static inline void rkcif_stream_return_buffer(struct rkcif_buffer *buffer,
+ enum vb2_buffer_state state)
+{
+ struct vb2_v4l2_buffer *vb = &buffer->vb;
+
+ vb2_buffer_done(&vb->vb2_buf, state);
+}
+
+static void rkcif_stream_complete_buffer(struct rkcif_stream *stream,
+ struct rkcif_buffer *buffer)
+{
+ struct vb2_v4l2_buffer *vb = &buffer->vb;
+
+ vb->vb2_buf.timestamp = ktime_get_ns();
+ vb->sequence = stream->frame_idx;
+ vb2_buffer_done(&vb->vb2_buf, VB2_BUF_STATE_DONE);
+ stream->frame_idx++;
+}
+
+void rkcif_stream_pingpong(struct rkcif_stream *stream)
+{
+ struct rkcif_buffer *buffer;
+
+ buffer = stream->buffers[stream->frame_phase];
+ if (!buffer->is_dummy)
+ rkcif_stream_complete_buffer(stream, buffer);
+
+ buffer = rkcif_stream_pop_buffer(stream);
+ if (buffer) {
+ stream->buffers[stream->frame_phase] = buffer;
+ stream->buffers[stream->frame_phase]->is_dummy = false;
+ } else {
+ stream->buffers[stream->frame_phase] = &stream->dummy.buffer;
+ stream->buffers[stream->frame_phase]->is_dummy = true;
+ dev_dbg(stream->rkcif->dev,
+ "no buffer available, frame will be dropped\n");
+ }
+
+ if (stream->queue_buffer)
+ stream->queue_buffer(stream, stream->frame_phase);
+
+ stream->frame_phase = 1 - stream->frame_phase;
+}
+
+static int rkcif_stream_init_buffers(struct rkcif_stream *stream)
+{
+ struct v4l2_pix_format_mplane *pix = &stream->pix;
+
+ stream->buffers[0] = rkcif_stream_pop_buffer(stream);
+ if (!stream->buffers[0])
+ goto err_buff_0;
+
+ stream->buffers[1] = rkcif_stream_pop_buffer(stream);
+ if (!stream->buffers[1])
+ goto err_buff_1;
+
+ if (stream->queue_buffer) {
+ stream->queue_buffer(stream, 0);
+ stream->queue_buffer(stream, 1);
+ }
+
+ stream->dummy.size = pix->num_planes * pix->plane_fmt[0].sizeimage;
+ stream->dummy.vaddr =
+ dma_alloc_attrs(stream->rkcif->dev, stream->dummy.size,
+ &stream->dummy.buffer.buff_addr[0], GFP_KERNEL,
+ DMA_ATTR_NO_KERNEL_MAPPING);
+ if (!stream->dummy.vaddr)
+ goto err_dummy;
+
+ for (unsigned int i = 1; i < pix->num_planes; i++)
+ stream->dummy.buffer.buff_addr[i] =
+ stream->dummy.buffer.buff_addr[i - 1] +
+ pix->plane_fmt[i - 1].bytesperline * pix->height;
+
+ return 0;
+
+err_dummy:
+ rkcif_stream_return_buffer(stream->buffers[1], VB2_BUF_STATE_QUEUED);
+ stream->buffers[1] = NULL;
+
+err_buff_1:
+ rkcif_stream_return_buffer(stream->buffers[0], VB2_BUF_STATE_QUEUED);
+ stream->buffers[0] = NULL;
+err_buff_0:
+ return -EINVAL;
+}
+
+static void rkcif_stream_return_all_buffers(struct rkcif_stream *stream,
+ enum vb2_buffer_state state)
+{
+ struct rkcif_buffer *buffer;
+
+ if (stream->buffers[0] && !stream->buffers[0]->is_dummy) {
+ rkcif_stream_return_buffer(stream->buffers[0], state);
+ stream->buffers[0] = NULL;
+ }
+
+ if (stream->buffers[1] && !stream->buffers[1]->is_dummy) {
+ rkcif_stream_return_buffer(stream->buffers[1], state);
+ stream->buffers[1] = NULL;
+ }
+
+ while ((buffer = rkcif_stream_pop_buffer(stream)))
+ rkcif_stream_return_buffer(buffer, state);
+
+ if (stream->dummy.vaddr) {
+ dma_free_attrs(stream->rkcif->dev, stream->dummy.size,
+ stream->dummy.vaddr,
+ stream->dummy.buffer.buff_addr[0],
+ DMA_ATTR_NO_KERNEL_MAPPING);
+ stream->dummy.vaddr = NULL;
+ }
+}
+
+static int rkcif_stream_setup_queue(struct vb2_queue *queue,
+ unsigned int *num_buffers,
+ unsigned int *num_planes,
+ unsigned int sizes[],
+ struct device *alloc_devs[])
+{
+ struct rkcif_stream *stream = queue->drv_priv;
+ struct v4l2_pix_format_mplane *pix = &stream->pix;
+
+ if (*num_planes) {
+ if (*num_planes != pix->num_planes)
+ return -EINVAL;
+
+ for (unsigned int i = 0; i < pix->num_planes; i++)
+ if (sizes[i] < pix->plane_fmt[i].sizeimage)
+ return -EINVAL;
+ } else {
+ *num_planes = pix->num_planes;
+ for (unsigned int i = 0; i < pix->num_planes; i++)
+ sizes[i] = pix->plane_fmt[i].sizeimage;
+ }
+
+ return 0;
+}
+
+static int rkcif_stream_prepare_buffer(struct vb2_buffer *vb)
+{
+ struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+ struct rkcif_buffer *buffer = to_rkcif_buffer(vbuf);
+ struct rkcif_stream *stream = vb->vb2_queue->drv_priv;
+ const struct rkcif_output_fmt *fmt;
+ struct v4l2_pix_format_mplane *pix = &stream->pix;
+ unsigned int i;
+
+ memset(buffer->buff_addr, 0, sizeof(buffer->buff_addr));
+ for (i = 0; i < pix->num_planes; i++)
+ buffer->buff_addr[i] = vb2_dma_contig_plane_dma_addr(vb, i);
+
+ /* apply fallback for non-mplane formats, if required */
+ if (pix->num_planes == 1) {
+ fmt = rkcif_stream_find_output_fmt(stream, true,
+ pix->pixelformat);
+ for (i = 1; i < fmt->cplanes; i++)
+ buffer->buff_addr[i] =
+ buffer->buff_addr[i - 1] +
+ pix->plane_fmt[i - 1].bytesperline *
+ pix->height;
+ }
+
+ for (i = 0; i < pix->num_planes; i++) {
+ unsigned long size = pix->plane_fmt[i].sizeimage;
+
+ if (vb2_plane_size(vb, i) < size) {
+ dev_err(stream->rkcif->dev,
+ "user buffer too small (%ld < %ld)\n",
+ vb2_plane_size(vb, i), size);
+ return -EINVAL;
+ }
+
+ vb2_set_plane_payload(vb, i, size);
+ }
+
+ vbuf->field = V4L2_FIELD_NONE;
+
+ return 0;
+}
+
+static void rkcif_stream_queue_buffer(struct vb2_buffer *vb)
+{
+ struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+ struct rkcif_buffer *buffer = to_rkcif_buffer(vbuf);
+ struct rkcif_stream *stream = vb->vb2_queue->drv_priv;
+
+ rkcif_stream_push_buffer(stream, buffer);
+}
+
+static int rkcif_stream_start_streaming(struct vb2_queue *queue,
+ unsigned int count)
+{
+ struct rkcif_stream *stream = queue->drv_priv;
+ struct rkcif_device *rkcif = stream->rkcif;
+ u64 mask;
+ int ret;
+
+ stream->frame_idx = 0;
+ stream->frame_phase = 0;
+
+ ret = video_device_pipeline_start(&stream->vdev, &stream->pipeline);
+ if (ret) {
+ dev_err(rkcif->dev, "failed to start pipeline %d\n", ret);
+ goto err_out;
+ }
+
+ ret = pm_runtime_resume_and_get(rkcif->dev);
+ if (ret < 0) {
+ dev_err(rkcif->dev, "failed to get runtime pm, %d\n", ret);
+ goto err_pipeline_stop;
+ }
+
+ ret = rkcif_stream_init_buffers(stream);
+ if (ret)
+ goto err_runtime_put;
+
+ if (stream->start_streaming) {
+ ret = stream->start_streaming(stream);
+ if (ret < 0)
+ goto err_runtime_put;
+ }
+
+ mask = BIT_ULL(stream->id);
+ ret = v4l2_subdev_enable_streams(&stream->interface->sd,
+ RKCIF_IF_PAD_SRC, mask);
+ if (ret < 0)
+ goto err_stop_stream;
+
+ return 0;
+
+err_stop_stream:
+ if (stream->stop_streaming)
+ stream->stop_streaming(stream);
+err_runtime_put:
+ pm_runtime_put(rkcif->dev);
+err_pipeline_stop:
+ video_device_pipeline_stop(&stream->vdev);
+err_out:
+ rkcif_stream_return_all_buffers(stream, VB2_BUF_STATE_QUEUED);
+ return ret;
+}
+
+static void rkcif_stream_stop_streaming(struct vb2_queue *queue)
+{
+ struct rkcif_stream *stream = queue->drv_priv;
+ struct rkcif_device *rkcif = stream->rkcif;
+ u64 mask;
+ int ret;
+
+ mask = BIT_ULL(stream->id);
+ v4l2_subdev_disable_streams(&stream->interface->sd, RKCIF_IF_PAD_SRC,
+ mask);
+
+ stream->stopping = true;
+ ret = wait_event_timeout(stream->wq_stopped, !stream->stopping,
+ msecs_to_jiffies(1000));
+
+ if (!ret && stream->stop_streaming)
+ stream->stop_streaming(stream);
+
+ pm_runtime_put(rkcif->dev);
+
+ rkcif_stream_return_all_buffers(stream, VB2_BUF_STATE_ERROR);
+
+ video_device_pipeline_stop(&stream->vdev);
+}
+
+static const struct vb2_ops rkcif_stream_vb2_ops = {
+ .queue_setup = rkcif_stream_setup_queue,
+ .buf_prepare = rkcif_stream_prepare_buffer,
+ .buf_queue = rkcif_stream_queue_buffer,
+ .start_streaming = rkcif_stream_start_streaming,
+ .stop_streaming = rkcif_stream_stop_streaming,
+};
+
+static int rkcif_stream_fill_format(struct rkcif_stream *stream,
+ struct v4l2_pix_format_mplane *pix)
+{
+ const struct rkcif_output_fmt *fmt;
+ u32 height, width;
+ int ret;
+
+ fmt = rkcif_stream_find_output_fmt(stream, true, pix->pixelformat);
+ height = clamp_t(u32, pix->height, CIF_MIN_HEIGHT, CIF_MAX_HEIGHT);
+ width = clamp_t(u32, pix->width, CIF_MIN_WIDTH, CIF_MAX_WIDTH);
+ ret = v4l2_fill_pixfmt_mp(pix, fmt->fourcc, width, height);
+ if (ret)
+ return ret;
+
+ pix->field = V4L2_FIELD_NONE;
+
+ return 0;
+}
+
+static int rkcif_stream_try_format(struct file *file, void *fh,
+ struct v4l2_format *f)
+{
+ struct rkcif_stream *stream = video_drvdata(file);
+ struct v4l2_pix_format_mplane *pix = &f->fmt.pix_mp;
+
+ return rkcif_stream_fill_format(stream, pix);
+}
+
+static int rkcif_stream_set_format(struct file *file, void *priv,
+ struct v4l2_format *f)
+{
+ struct rkcif_stream *stream = video_drvdata(file);
+ struct v4l2_pix_format_mplane *pix = &f->fmt.pix_mp;
+ int ret;
+
+ if (vb2_is_busy(&stream->buf_queue))
+ return -EBUSY;
+
+ ret = rkcif_stream_try_format(file, priv, f);
+ if (ret)
+ return ret;
+
+ stream->pix = *pix;
+
+ return 0;
+}
+
+static int rkcif_stream_get_format(struct file *file, void *fh,
+ struct v4l2_format *f)
+{
+ struct rkcif_stream *stream = video_drvdata(file);
+
+ f->fmt.pix_mp = stream->pix;
+
+ return 0;
+}
+
+static int rkcif_stream_enum_formats(struct file *file, void *priv,
+ struct v4l2_fmtdesc *f)
+{
+ struct rkcif_stream *stream = video_drvdata(file);
+
+ if (f->index >= stream->out_fmts_num)
+ return -EINVAL;
+
+ f->pixelformat = stream->out_fmts[f->index].fourcc;
+
+ return 0;
+}
+
+static int rkcif_stream_enum_framesizes(struct file *file, void *fh,
+ struct v4l2_frmsizeenum *fsize)
+{
+ struct rkcif_stream *stream = video_drvdata(file);
+
+ if (fsize->index > 0)
+ return -EINVAL;
+
+ if (!rkcif_stream_find_output_fmt(stream, false, fsize->pixel_format))
+ return -EINVAL;
+
+ fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
+ fsize->stepwise.min_width = CIF_MIN_WIDTH;
+ fsize->stepwise.max_width = CIF_MAX_WIDTH;
+ fsize->stepwise.step_width = 8;
+ fsize->stepwise.min_height = CIF_MIN_HEIGHT;
+ fsize->stepwise.max_height = CIF_MAX_HEIGHT;
+ fsize->stepwise.step_height = 8;
+
+ return 0;
+}
+
+static int rkcif_stream_querycap(struct file *file, void *priv,
+ struct v4l2_capability *cap)
+{
+ struct rkcif_stream *stream = video_drvdata(file);
+ struct device *dev = stream->rkcif->dev;
+
+ strscpy(cap->driver, dev->driver->name, sizeof(cap->driver));
+ strscpy(cap->card, dev->driver->name, sizeof(cap->card));
+
+ return 0;
+}
+
+static const struct v4l2_ioctl_ops rkcif_stream_ioctl_ops = {
+ .vidioc_reqbufs = vb2_ioctl_reqbufs,
+ .vidioc_querybuf = vb2_ioctl_querybuf,
+ .vidioc_create_bufs = vb2_ioctl_create_bufs,
+ .vidioc_qbuf = vb2_ioctl_qbuf,
+ .vidioc_expbuf = vb2_ioctl_expbuf,
+ .vidioc_dqbuf = vb2_ioctl_dqbuf,
+ .vidioc_prepare_buf = vb2_ioctl_prepare_buf,
+ .vidioc_streamon = vb2_ioctl_streamon,
+ .vidioc_streamoff = vb2_ioctl_streamoff,
+ .vidioc_try_fmt_vid_cap_mplane = rkcif_stream_try_format,
+ .vidioc_s_fmt_vid_cap_mplane = rkcif_stream_set_format,
+ .vidioc_g_fmt_vid_cap_mplane = rkcif_stream_get_format,
+ .vidioc_enum_fmt_vid_cap = rkcif_stream_enum_formats,
+ .vidioc_enum_framesizes = rkcif_stream_enum_framesizes,
+ .vidioc_querycap = rkcif_stream_querycap,
+};
+
+static int rkcif_stream_link_validate(struct media_link *link)
+{
+ struct video_device *vdev =
+ media_entity_to_video_device(link->sink->entity);
+ struct v4l2_mbus_framefmt *source_fmt;
+ struct v4l2_subdev *sd;
+ struct v4l2_subdev_state *state;
+ struct rkcif_stream *stream = to_rkcif_stream(vdev);
+ int ret = -EINVAL;
+
+ if (!media_entity_remote_source_pad_unique(link->sink->entity))
+ return -ENOTCONN;
+
+ sd = media_entity_to_v4l2_subdev(link->source->entity);
+
+ state = v4l2_subdev_lock_and_get_active_state(sd);
+
+ source_fmt = v4l2_subdev_state_get_format(state, link->source->index,
+ stream->id);
+ if (!source_fmt)
+ goto out;
+
+ if (source_fmt->height != stream->pix.height ||
+ source_fmt->width != stream->pix.width) {
+ dev_dbg(stream->rkcif->dev,
+ "link '%s':%u -> '%s':%u not valid: %ux%u != %ux%u\n",
+ link->source->entity->name, link->source->index,
+ link->sink->entity->name, link->sink->index,
+ source_fmt->width, source_fmt->height,
+ stream->pix.width, stream->pix.height);
+ goto out;
+ }
+
+ ret = 0;
+
+out:
+ v4l2_subdev_unlock_state(state);
+ return ret;
+}
+
+static const struct media_entity_operations rkcif_stream_media_ops = {
+ .link_validate = rkcif_stream_link_validate,
+};
+
+static const struct v4l2_file_operations rkcif_stream_file_ops = {
+ .open = v4l2_fh_open,
+ .release = vb2_fop_release,
+ .unlocked_ioctl = video_ioctl2,
+ .poll = vb2_fop_poll,
+ .mmap = vb2_fop_mmap,
+};
+
+static int rkcif_stream_init_vb2_queue(struct vb2_queue *q,
+ struct rkcif_stream *stream)
+{
+ q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+ q->io_modes = VB2_MMAP | VB2_DMABUF;
+ q->drv_priv = stream;
+ q->ops = &rkcif_stream_vb2_ops;
+ q->mem_ops = &vb2_dma_contig_memops;
+ q->buf_struct_size = sizeof(struct rkcif_buffer);
+ q->min_queued_buffers = CIF_REQ_BUFS_MIN;
+ q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+ q->lock = &stream->vlock;
+ q->dev = stream->rkcif->dev;
+
+ return vb2_queue_init(q);
+}
+
+int rkcif_stream_register(struct rkcif_device *rkcif,
+ struct rkcif_stream *stream)
+{
+ struct rkcif_interface *interface = stream->interface;
+ struct v4l2_device *v4l2_dev = &rkcif->v4l2_dev;
+ struct video_device *vdev = &stream->vdev;
+ u32 link_flags = 0;
+ int ret;
+
+ stream->rkcif = rkcif;
+
+ INIT_LIST_HEAD(&stream->driver_queue);
+ spin_lock_init(&stream->driver_queue_lock);
+
+ init_waitqueue_head(&stream->wq_stopped);
+
+ mutex_init(&stream->vlock);
+
+ vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE_MPLANE | V4L2_CAP_STREAMING |
+ V4L2_CAP_IO_MC;
+ vdev->entity.ops = &rkcif_stream_media_ops;
+ vdev->fops = &rkcif_stream_file_ops;
+ vdev->ioctl_ops = &rkcif_stream_ioctl_ops;
+ vdev->lock = &stream->vlock;
+ vdev->minor = -1;
+ vdev->release = video_device_release_empty;
+ vdev->v4l2_dev = v4l2_dev;
+ vdev->vfl_dir = VFL_DIR_RX;
+ video_set_drvdata(vdev, stream);
+
+ stream->pad.flags = MEDIA_PAD_FL_SINK;
+
+ stream->pix.height = CIF_MIN_HEIGHT;
+ stream->pix.width = CIF_MIN_WIDTH;
+ rkcif_stream_fill_format(stream, &stream->pix);
+
+ rkcif_stream_init_vb2_queue(&stream->buf_queue, stream);
+
+ vdev->queue = &stream->buf_queue;
+ if (interface->type == RKCIF_IF_DVP)
+ snprintf(vdev->name, sizeof(vdev->name), "rkcif-dvp0-id%d",
+ stream->id);
+ else if (interface->type == RKCIF_IF_MIPI)
+ snprintf(vdev->name, sizeof(vdev->name), "rkcif-mipi%d-id%d",
+ interface->index - RKCIF_MIPI_BASE, stream->id);
+
+ ret = media_entity_pads_init(&vdev->entity, 1, &stream->pad);
+ if (ret < 0) {
+ dev_err(rkcif->dev,
+ "failed to initialize stream media pad: %d\n", ret);
+ return ret;
+ }
+
+ ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
+ if (ret < 0) {
+ dev_err(rkcif->dev, "failed to register video device: %d\n",
+ ret);
+ goto err_media_entity_cleanup;
+ }
+
+ /* enable only stream ID0 by default */
+ if (stream->id == RKCIF_ID0)
+ link_flags |= MEDIA_LNK_FL_ENABLED;
+
+ ret = media_create_pad_link(&interface->sd.entity, RKCIF_IF_PAD_SRC,
+ &stream->vdev.entity, 0, link_flags);
+ if (ret) {
+ dev_err(rkcif->dev, "failed to link stream media pad: %d\n",
+ ret);
+ goto err_video_unregister;
+ }
+
+ v4l2_info(v4l2_dev, "registered %s as /dev/video%d\n", vdev->name,
+ vdev->num);
+
+ return 0;
+
+err_video_unregister:
+ video_unregister_device(&stream->vdev);
+err_media_entity_cleanup:
+ media_entity_cleanup(&stream->vdev.entity);
+ return ret;
+}
+
+void rkcif_stream_unregister(struct rkcif_stream *stream)
+{
+ video_unregister_device(&stream->vdev);
+ media_entity_cleanup(&stream->vdev.entity);
+}
+
+const struct rkcif_output_fmt *
+rkcif_stream_find_output_fmt(struct rkcif_stream *stream, bool ret_def,
+ u32 pixelfmt)
+{
+ const struct rkcif_output_fmt *fmt;
+
+ WARN_ON(stream->out_fmts_num == 0);
+
+ for (unsigned int i = 0; i < stream->out_fmts_num; i++) {
+ fmt = &stream->out_fmts[i];
+ if (fmt->fourcc == pixelfmt)
+ return fmt;
+ }
+
+ if (ret_def)
+ return &stream->out_fmts[0];
+ else
+ return NULL;
+}