mirror of https://github.com/FFmpeg/FFmpeg.git
Support for this device has been removed in the Linux kernel since v2.6.37. dv1394 has been superseded by libiec61883 which is functionally equivalent. Signed-off-by: Josh de Kock <josh@itanimul.li> Signed-off-by: Diego Biurrun <diego@biurrun.de>pull/272/head
Josh de Kock
7 years ago
committed by
Diego Biurrun
parent
543f00c78e
commit
762ab2de6e
8 changed files with 1 additions and 606 deletions
@ -1,238 +0,0 @@ |
|||||||
/*
|
|
||||||
* Linux DV1394 interface |
|
||||||
* Copyright (c) 2003 Max Krasnyansky <maxk@qualcomm.com> |
|
||||||
* |
|
||||||
* 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 |
|
||||||
*/ |
|
||||||
|
|
||||||
#include "config.h" |
|
||||||
#include <unistd.h> |
|
||||||
#include <fcntl.h> |
|
||||||
#include <errno.h> |
|
||||||
#include <poll.h> |
|
||||||
#include <sys/ioctl.h> |
|
||||||
#include <sys/mman.h> |
|
||||||
|
|
||||||
#include "libavutil/internal.h" |
|
||||||
#include "libavutil/log.h" |
|
||||||
#include "libavutil/opt.h" |
|
||||||
#include "libavformat/avformat.h" |
|
||||||
#include "libavformat/dv.h" |
|
||||||
#include "dv1394.h" |
|
||||||
|
|
||||||
struct dv1394_data { |
|
||||||
AVClass *class; |
|
||||||
int fd; |
|
||||||
int channel; |
|
||||||
int format; |
|
||||||
|
|
||||||
uint8_t *ring; /* Ring buffer */ |
|
||||||
int index; /* Current frame index */ |
|
||||||
int avail; /* Number of frames available for reading */ |
|
||||||
int done; /* Number of completed frames */ |
|
||||||
|
|
||||||
DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */ |
|
||||||
}; |
|
||||||
|
|
||||||
/*
|
|
||||||
* The trick here is to kludge around well known problem with kernel Ooopsing |
|
||||||
* when you try to capture PAL on a device node configure for NTSC. That's |
|
||||||
* why we have to configure the device node for PAL, and then read only NTSC |
|
||||||
* amount of data. |
|
||||||
*/ |
|
||||||
static int dv1394_reset(struct dv1394_data *dv) |
|
||||||
{ |
|
||||||
struct dv1394_init init; |
|
||||||
|
|
||||||
init.channel = dv->channel; |
|
||||||
init.api_version = DV1394_API_VERSION; |
|
||||||
init.n_frames = DV1394_RING_FRAMES; |
|
||||||
init.format = DV1394_PAL; |
|
||||||
|
|
||||||
if (ioctl(dv->fd, DV1394_INIT, &init) < 0) |
|
||||||
return -1; |
|
||||||
|
|
||||||
dv->avail = dv->done = 0; |
|
||||||
return 0; |
|
||||||
} |
|
||||||
|
|
||||||
static int dv1394_start(struct dv1394_data *dv) |
|
||||||
{ |
|
||||||
/* Tell DV1394 driver to enable receiver */ |
|
||||||
if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) { |
|
||||||
av_log(NULL, AV_LOG_ERROR, "Failed to start receiver: %s\n", strerror(errno)); |
|
||||||
return -1; |
|
||||||
} |
|
||||||
return 0; |
|
||||||
} |
|
||||||
|
|
||||||
static int dv1394_read_header(AVFormatContext * context) |
|
||||||
{ |
|
||||||
struct dv1394_data *dv = context->priv_data; |
|
||||||
|
|
||||||
dv->dv_demux = avpriv_dv_init_demux(context); |
|
||||||
if (!dv->dv_demux) |
|
||||||
goto failed; |
|
||||||
|
|
||||||
/* Open and initialize DV1394 device */ |
|
||||||
dv->fd = avpriv_open(context->filename, O_RDONLY); |
|
||||||
if (dv->fd < 0) { |
|
||||||
av_log(context, AV_LOG_ERROR, "Failed to open DV interface: %s\n", strerror(errno)); |
|
||||||
goto failed; |
|
||||||
} |
|
||||||
|
|
||||||
if (dv1394_reset(dv) < 0) { |
|
||||||
av_log(context, AV_LOG_ERROR, "Failed to initialize DV interface: %s\n", strerror(errno)); |
|
||||||
goto failed; |
|
||||||
} |
|
||||||
|
|
||||||
dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES, |
|
||||||
PROT_READ, MAP_PRIVATE, dv->fd, 0); |
|
||||||
if (dv->ring == MAP_FAILED) { |
|
||||||
av_log(context, AV_LOG_ERROR, "Failed to mmap DV ring buffer: %s\n", strerror(errno)); |
|
||||||
goto failed; |
|
||||||
} |
|
||||||
|
|
||||||
if (dv1394_start(dv) < 0) |
|
||||||
goto failed; |
|
||||||
|
|
||||||
return 0; |
|
||||||
|
|
||||||
failed: |
|
||||||
close(dv->fd); |
|
||||||
return AVERROR(EIO); |
|
||||||
} |
|
||||||
|
|
||||||
static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt) |
|
||||||
{ |
|
||||||
struct dv1394_data *dv = context->priv_data; |
|
||||||
int size; |
|
||||||
|
|
||||||
size = avpriv_dv_get_packet(dv->dv_demux, pkt); |
|
||||||
if (size > 0) |
|
||||||
return size; |
|
||||||
|
|
||||||
if (!dv->avail) { |
|
||||||
struct dv1394_status s; |
|
||||||
struct pollfd p; |
|
||||||
|
|
||||||
if (dv->done) { |
|
||||||
/* Request more frames */ |
|
||||||
if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) { |
|
||||||
/* This usually means that ring buffer overflowed.
|
|
||||||
* We have to reset :(. |
|
||||||
*/ |
|
||||||
|
|
||||||
av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n"); |
|
||||||
|
|
||||||
dv1394_reset(dv); |
|
||||||
dv1394_start(dv); |
|
||||||
} |
|
||||||
dv->done = 0; |
|
||||||
} |
|
||||||
|
|
||||||
/* Wait until more frames are available */ |
|
||||||
restart_poll: |
|
||||||
p.fd = dv->fd; |
|
||||||
p.events = POLLIN | POLLERR | POLLHUP; |
|
||||||
if (poll(&p, 1, -1) < 0) { |
|
||||||
if (errno == EAGAIN || errno == EINTR) |
|
||||||
goto restart_poll; |
|
||||||
av_log(context, AV_LOG_ERROR, "Poll failed: %s\n", strerror(errno)); |
|
||||||
return AVERROR(EIO); |
|
||||||
} |
|
||||||
|
|
||||||
if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) { |
|
||||||
av_log(context, AV_LOG_ERROR, "Failed to get status: %s\n", strerror(errno)); |
|
||||||
return AVERROR(EIO); |
|
||||||
} |
|
||||||
av_log(context, AV_LOG_TRACE, "DV1394: status\n" |
|
||||||
"\tactive_frame\t%d\n" |
|
||||||
"\tfirst_clear_frame\t%d\n" |
|
||||||
"\tn_clear_frames\t%d\n" |
|
||||||
"\tdropped_frames\t%d\n", |
|
||||||
s.active_frame, s.first_clear_frame, |
|
||||||
s.n_clear_frames, s.dropped_frames); |
|
||||||
|
|
||||||
dv->avail = s.n_clear_frames; |
|
||||||
dv->index = s.first_clear_frame; |
|
||||||
dv->done = 0; |
|
||||||
|
|
||||||
if (s.dropped_frames) { |
|
||||||
av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n", |
|
||||||
s.dropped_frames); |
|
||||||
|
|
||||||
dv1394_reset(dv); |
|
||||||
dv1394_start(dv); |
|
||||||
} |
|
||||||
} |
|
||||||
|
|
||||||
av_log(context, AV_LOG_TRACE, "index %d, avail %d, done %d\n", dv->index, dv->avail, |
|
||||||
dv->done); |
|
||||||
|
|
||||||
size = avpriv_dv_produce_packet(dv->dv_demux, pkt, |
|
||||||
dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE), |
|
||||||
DV1394_PAL_FRAME_SIZE); |
|
||||||
dv->index = (dv->index + 1) % DV1394_RING_FRAMES; |
|
||||||
dv->done++; dv->avail--; |
|
||||||
|
|
||||||
return size; |
|
||||||
} |
|
||||||
|
|
||||||
static int dv1394_close(AVFormatContext * context) |
|
||||||
{ |
|
||||||
struct dv1394_data *dv = context->priv_data; |
|
||||||
|
|
||||||
/* Shutdown DV1394 receiver */ |
|
||||||
if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0) |
|
||||||
av_log(context, AV_LOG_ERROR, "Failed to shutdown DV1394: %s\n", strerror(errno)); |
|
||||||
|
|
||||||
/* Unmap ring buffer */ |
|
||||||
if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0) |
|
||||||
av_log(context, AV_LOG_ERROR, "Failed to munmap DV1394 ring buffer: %s\n", strerror(errno)); |
|
||||||
|
|
||||||
close(dv->fd); |
|
||||||
av_free(dv->dv_demux); |
|
||||||
|
|
||||||
return 0; |
|
||||||
} |
|
||||||
|
|
||||||
static const AVOption options[] = { |
|
||||||
{ "standard", "", offsetof(struct dv1394_data, format), AV_OPT_TYPE_INT, {.i64 = DV1394_NTSC}, DV1394_NTSC, DV1394_PAL, AV_OPT_FLAG_DECODING_PARAM, "standard" }, |
|
||||||
{ "PAL", "", 0, AV_OPT_TYPE_CONST, {.i64 = DV1394_PAL}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" }, |
|
||||||
{ "NTSC", "", 0, AV_OPT_TYPE_CONST, {.i64 = DV1394_NTSC}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" }, |
|
||||||
{ "channel", "", offsetof(struct dv1394_data, channel), AV_OPT_TYPE_INT, {.i64 = DV1394_DEFAULT_CHANNEL}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM }, |
|
||||||
{ NULL }, |
|
||||||
}; |
|
||||||
|
|
||||||
static const AVClass dv1394_class = { |
|
||||||
.class_name = "DV1394 indev", |
|
||||||
.item_name = av_default_item_name, |
|
||||||
.option = options, |
|
||||||
.version = LIBAVUTIL_VERSION_INT, |
|
||||||
}; |
|
||||||
|
|
||||||
AVInputFormat ff_dv1394_demuxer = { |
|
||||||
.name = "dv1394", |
|
||||||
.long_name = NULL_IF_CONFIG_SMALL("DV1394 A/V grab"), |
|
||||||
.priv_data_size = sizeof(struct dv1394_data), |
|
||||||
.read_header = dv1394_read_header, |
|
||||||
.read_packet = dv1394_read_packet, |
|
||||||
.read_close = dv1394_close, |
|
||||||
.flags = AVFMT_NOFILE, |
|
||||||
.priv_class = &dv1394_class, |
|
||||||
}; |
|
||||||
@ -1,357 +0,0 @@ |
|||||||
/*
|
|
||||||
* DV input/output over IEEE 1394 on OHCI chips |
|
||||||
* Copyright (C)2001 Daniel Maas <dmaas@dcine.com> |
|
||||||
* receive, proc_fs by Dan Dennedy <dan@dennedy.org> |
|
||||||
* |
|
||||||
* based on: |
|
||||||
* video1394.h - driver for OHCI 1394 boards |
|
||||||
* Copyright (C)1999,2000 Sebastien Rougeaux <sebastien.rougeaux@anu.edu.au> |
|
||||||
* Peter Schlaile <udbz@rz.uni-karlsruhe.de> |
|
||||||
* |
|
||||||
* 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 |
|
||||||
*/ |
|
||||||
|
|
||||||
#ifndef AVDEVICE_DV1394_H |
|
||||||
#define AVDEVICE_DV1394_H |
|
||||||
|
|
||||||
#define DV1394_DEFAULT_CHANNEL 63 |
|
||||||
#define DV1394_DEFAULT_CARD 0 |
|
||||||
#define DV1394_RING_FRAMES 20 |
|
||||||
|
|
||||||
#define DV1394_WIDTH 720 |
|
||||||
#define DV1394_NTSC_HEIGHT 480 |
|
||||||
#define DV1394_PAL_HEIGHT 576 |
|
||||||
|
|
||||||
/* This is the public user-space interface. Try not to break it. */ |
|
||||||
|
|
||||||
#define DV1394_API_VERSION 0x20011127 |
|
||||||
|
|
||||||
/* ********************
|
|
||||||
** ** |
|
||||||
** DV1394 API ** |
|
||||||
** ** |
|
||||||
******************** |
|
||||||
|
|
||||||
There are two methods of operating the DV1394 DV output device. |
|
||||||
|
|
||||||
1) |
|
||||||
|
|
||||||
The simplest is an interface based on write(): simply write |
|
||||||
full DV frames of data to the device, and they will be transmitted |
|
||||||
as quickly as possible. The FD may be set for non-blocking I/O, |
|
||||||
in which case you can use select() or poll() to wait for output |
|
||||||
buffer space. |
|
||||||
|
|
||||||
To set the DV output parameters (e.g. whether you want NTSC or PAL |
|
||||||
video), use the DV1394_INIT ioctl, passing in the parameters you |
|
||||||
want in a struct dv1394_init. |
|
||||||
|
|
||||||
Example 1: |
|
||||||
To play a raw .DV file: cat foo.DV > /dev/dv1394 |
|
||||||
(cat will use write() internally) |
|
||||||
|
|
||||||
Example 2: |
|
||||||
static struct dv1394_init init = { |
|
||||||
0x63, (broadcast channel) |
|
||||||
4, (four-frame ringbuffer) |
|
||||||
DV1394_NTSC, (send NTSC video) |
|
||||||
0, 0 (default empty packet rate) |
|
||||||
} |
|
||||||
|
|
||||||
ioctl(fd, DV1394_INIT, &init); |
|
||||||
|
|
||||||
while(1) { |
|
||||||
read( <a raw DV file>, buf, DV1394_NTSC_FRAME_SIZE ); |
|
||||||
write( <the dv1394 FD>, buf, DV1394_NTSC_FRAME_SIZE ); |
|
||||||
} |
|
||||||
|
|
||||||
2) |
|
||||||
|
|
||||||
For more control over buffering, and to avoid unnecessary copies |
|
||||||
of the DV data, you can use the more sophisticated the mmap() interface. |
|
||||||
First, call the DV1394_INIT ioctl to specify your parameters, |
|
||||||
including the number of frames in the ringbuffer. Then, calling mmap() |
|
||||||
on the dv1394 device will give you direct access to the ringbuffer |
|
||||||
from which the DV card reads your frame data. |
|
||||||
|
|
||||||
The ringbuffer is simply one large, contiguous region of memory |
|
||||||
containing two or more frames of packed DV data. Each frame of DV data |
|
||||||
is 120000 bytes (NTSC) or 144000 bytes (PAL). |
|
||||||
|
|
||||||
Fill one or more frames in the ringbuffer, then use the DV1394_SUBMIT_FRAMES |
|
||||||
ioctl to begin I/O. You can use either the DV1394_WAIT_FRAMES ioctl |
|
||||||
or select()/poll() to wait until the frames are transmitted. Next, you'll |
|
||||||
need to call the DV1394_GET_STATUS ioctl to determine which ringbuffer |
|
||||||
frames are clear (ready to be filled with new DV data). Finally, use |
|
||||||
DV1394_SUBMIT_FRAMES again to send the new data to the DV output. |
|
||||||
|
|
||||||
|
|
||||||
Example: here is what a four-frame ringbuffer might look like |
|
||||||
during DV transmission: |
|
||||||
|
|
||||||
|
|
||||||
frame 0 frame 1 frame 2 frame 3 |
|
||||||
|
|
||||||
*--------------------------------------* |
|
||||||
| CLEAR | DV data | DV data | CLEAR | |
|
||||||
*--------------------------------------* |
|
||||||
<ACTIVE> |
|
||||||
|
|
||||||
transmission goes in this direction --->>> |
|
||||||
|
|
||||||
|
|
||||||
The DV hardware is currently transmitting the data in frame 1. |
|
||||||
Once frame 1 is finished, it will automatically transmit frame 2. |
|
||||||
(if frame 2 finishes before frame 3 is submitted, the device |
|
||||||
will continue to transmit frame 2, and will increase the dropped_frames |
|
||||||
counter each time it repeats the transmission). |
|
||||||
|
|
||||||
|
|
||||||
If you called DV1394_GET_STATUS at this instant, you would |
|
||||||
receive the following values: |
|
||||||
|
|
||||||
n_frames = 4 |
|
||||||
active_frame = 1 |
|
||||||
first_clear_frame = 3 |
|
||||||
n_clear_frames = 2 |
|
||||||
|
|
||||||
At this point, you should write new DV data into frame 3 and optionally |
|
||||||
frame 0. Then call DV1394_SUBMIT_FRAMES to inform the device that |
|
||||||
it may transmit the new frames. |
|
||||||
|
|
||||||
ERROR HANDLING |
|
||||||
|
|
||||||
An error (buffer underflow/overflow or a break in the DV stream due |
|
||||||
to a 1394 bus reset) can be detected by checking the dropped_frames |
|
||||||
field of struct dv1394_status (obtained through the |
|
||||||
DV1394_GET_STATUS ioctl). |
|
||||||
|
|
||||||
The best way to recover from such an error is to re-initialize |
|
||||||
dv1394, either by using the DV1394_INIT ioctl call, or closing the |
|
||||||
file descriptor and opening it again. (note that you must unmap all |
|
||||||
ringbuffer mappings when closing the file descriptor, or else |
|
||||||
dv1394 will still be considered 'in use'). |
|
||||||
|
|
||||||
MAIN LOOP |
|
||||||
|
|
||||||
For maximum efficiency and robustness against bus errors, you are |
|
||||||
advised to model the main loop of your application after the |
|
||||||
following pseudo-code example: |
|
||||||
|
|
||||||
(checks of system call return values omitted for brevity; always |
|
||||||
check return values in your code!) |
|
||||||
|
|
||||||
while( frames left ) { |
|
||||||
|
|
||||||
struct pollfd *pfd = ...; |
|
||||||
|
|
||||||
pfd->fd = dv1394_fd; |
|
||||||
pfd->revents = 0; |
|
||||||
pfd->events = POLLOUT | POLLIN; (OUT for transmit, IN for receive) |
|
||||||
|
|
||||||
(add other sources of I/O here) |
|
||||||
|
|
||||||
poll(pfd, 1, -1); (or select(); add a timeout if you want) |
|
||||||
|
|
||||||
if(pfd->revents) { |
|
||||||
struct dv1394_status status; |
|
||||||
|
|
||||||
ioctl(dv1394_fd, DV1394_GET_STATUS, &status); |
|
||||||
|
|
||||||
if(status.dropped_frames > 0) { |
|
||||||
reset_dv1394(); |
|
||||||
} else { |
|
||||||
int i; |
|
||||||
for (i = 0; i < status.n_clear_frames; i++) { |
|
||||||
copy_DV_frame(); |
|
||||||
} |
|
||||||
} |
|
||||||
} |
|
||||||
} |
|
||||||
|
|
||||||
where copy_DV_frame() reads or writes on the dv1394 file descriptor |
|
||||||
(read/write mode) or copies data to/from the mmap ringbuffer and |
|
||||||
then calls ioctl(DV1394_SUBMIT_FRAMES) to notify dv1394 that new |
|
||||||
frames are available (mmap mode). |
|
||||||
|
|
||||||
reset_dv1394() is called in the event of a buffer |
|
||||||
underflow/overflow or a halt in the DV stream (e.g. due to a 1394 |
|
||||||
bus reset). To guarantee recovery from the error, this function |
|
||||||
should close the dv1394 file descriptor (and munmap() all |
|
||||||
ringbuffer mappings, if you are using them), then re-open the |
|
||||||
dv1394 device (and re-map the ringbuffer). |
|
||||||
|
|
||||||
*/ |
|
||||||
|
|
||||||
|
|
||||||
/* maximum number of frames in the ringbuffer */ |
|
||||||
#define DV1394_MAX_FRAMES 32 |
|
||||||
|
|
||||||
/* number of *full* isochronous packets per DV frame */ |
|
||||||
#define DV1394_NTSC_PACKETS_PER_FRAME 250 |
|
||||||
#define DV1394_PAL_PACKETS_PER_FRAME 300 |
|
||||||
|
|
||||||
/* size of one frame's worth of DV data, in bytes */ |
|
||||||
#define DV1394_NTSC_FRAME_SIZE (480 * DV1394_NTSC_PACKETS_PER_FRAME) |
|
||||||
#define DV1394_PAL_FRAME_SIZE (480 * DV1394_PAL_PACKETS_PER_FRAME) |
|
||||||
|
|
||||||
|
|
||||||
/* ioctl() commands */ |
|
||||||
|
|
||||||
enum { |
|
||||||
/* I don't like using 0 as a valid ioctl() */ |
|
||||||
DV1394_INVALID = 0, |
|
||||||
|
|
||||||
|
|
||||||
/* get the driver ready to transmit video.
|
|
||||||
pass a struct dv1394_init* as the parameter (see below), |
|
||||||
or NULL to get default parameters */ |
|
||||||
DV1394_INIT, |
|
||||||
|
|
||||||
|
|
||||||
/* stop transmitting video and free the ringbuffer */ |
|
||||||
DV1394_SHUTDOWN, |
|
||||||
|
|
||||||
|
|
||||||
/* submit N new frames to be transmitted, where
|
|
||||||
the index of the first new frame is first_clear_buffer, |
|
||||||
and the index of the last new frame is |
|
||||||
(first_clear_buffer + N) % n_frames */ |
|
||||||
DV1394_SUBMIT_FRAMES, |
|
||||||
|
|
||||||
|
|
||||||
/* block until N buffers are clear (pass N as the parameter)
|
|
||||||
Because we re-transmit the last frame on underrun, there |
|
||||||
will at most be n_frames - 1 clear frames at any time */ |
|
||||||
DV1394_WAIT_FRAMES, |
|
||||||
|
|
||||||
/* capture new frames that have been received, where
|
|
||||||
the index of the first new frame is first_clear_buffer, |
|
||||||
and the index of the last new frame is |
|
||||||
(first_clear_buffer + N) % n_frames */ |
|
||||||
DV1394_RECEIVE_FRAMES, |
|
||||||
|
|
||||||
|
|
||||||
DV1394_START_RECEIVE, |
|
||||||
|
|
||||||
|
|
||||||
/* pass a struct dv1394_status* as the parameter (see below) */ |
|
||||||
DV1394_GET_STATUS, |
|
||||||
}; |
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
enum pal_or_ntsc { |
|
||||||
DV1394_NTSC = 0, |
|
||||||
DV1394_PAL |
|
||||||
}; |
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
/* this is the argument to DV1394_INIT */ |
|
||||||
struct dv1394_init { |
|
||||||
/* DV1394_API_VERSION */ |
|
||||||
unsigned int api_version; |
|
||||||
|
|
||||||
/* isochronous transmission channel to use */ |
|
||||||
unsigned int channel; |
|
||||||
|
|
||||||
/* number of frames in the ringbuffer. Must be at least 2
|
|
||||||
and at most DV1394_MAX_FRAMES. */ |
|
||||||
unsigned int n_frames; |
|
||||||
|
|
||||||
/* send/receive PAL or NTSC video format */ |
|
||||||
enum pal_or_ntsc format; |
|
||||||
|
|
||||||
/* the following are used only for transmission */ |
|
||||||
|
|
||||||
/* set these to zero unless you want a
|
|
||||||
non-default empty packet rate (see below) */ |
|
||||||
unsigned long cip_n; |
|
||||||
unsigned long cip_d; |
|
||||||
|
|
||||||
/* set this to zero unless you want a
|
|
||||||
non-default SYT cycle offset (default = 3 cycles) */ |
|
||||||
unsigned int syt_offset; |
|
||||||
}; |
|
||||||
|
|
||||||
/* NOTE: you may only allocate the DV frame ringbuffer once each time
|
|
||||||
you open the dv1394 device. DV1394_INIT will fail if you call it a |
|
||||||
second time with different 'n_frames' or 'format' arguments (which |
|
||||||
would imply a different size for the ringbuffer). If you need a |
|
||||||
different buffer size, simply close and re-open the device, then |
|
||||||
initialize it with your new settings. */ |
|
||||||
|
|
||||||
/* Q: What are cip_n and cip_d? */ |
|
||||||
|
|
||||||
/*
|
|
||||||
A: DV video streams do not utilize 100% of the potential bandwidth offered |
|
||||||
by IEEE 1394 (FireWire). To achieve the correct rate of data transmission, |
|
||||||
DV devices must periodically insert empty packets into the 1394 data stream. |
|
||||||
Typically there is one empty packet per 14-16 data-carrying packets. |
|
||||||
|
|
||||||
Some DV devices will accept a wide range of empty packet rates, while others |
|
||||||
require a precise rate. If the dv1394 driver produces empty packets at |
|
||||||
a rate that your device does not accept, you may see ugly patterns on the |
|
||||||
DV output, or even no output at all. |
|
||||||
|
|
||||||
The default empty packet insertion rate seems to work for many people; if |
|
||||||
your DV output is stable, you can simply ignore this discussion. However, |
|
||||||
we have exposed the empty packet rate as a parameter to support devices that |
|
||||||
do not work with the default rate. |
|
||||||
|
|
||||||
The decision to insert an empty packet is made with a numerator/denominator |
|
||||||
algorithm. Empty packets are produced at an average rate of CIP_N / CIP_D. |
|
||||||
You can alter the empty packet rate by passing non-zero values for cip_n |
|
||||||
and cip_d to the INIT ioctl. |
|
||||||
|
|
||||||
*/ |
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
struct dv1394_status { |
|
||||||
/* this embedded init struct returns the current dv1394
|
|
||||||
parameters in use */ |
|
||||||
struct dv1394_init init; |
|
||||||
|
|
||||||
/* the ringbuffer frame that is currently being
|
|
||||||
displayed. (-1 if the device is not transmitting anything) */ |
|
||||||
int active_frame; |
|
||||||
|
|
||||||
/* index of the first buffer (ahead of active_frame) that
|
|
||||||
is ready to be filled with data */ |
|
||||||
unsigned int first_clear_frame; |
|
||||||
|
|
||||||
/* how many buffers, including first_clear_buffer, are
|
|
||||||
ready to be filled with data */ |
|
||||||
unsigned int n_clear_frames; |
|
||||||
|
|
||||||
/* how many times the DV stream has underflowed, overflowed,
|
|
||||||
or otherwise encountered an error, since the previous call |
|
||||||
to DV1394_GET_STATUS */ |
|
||||||
unsigned int dropped_frames; |
|
||||||
|
|
||||||
/* N.B. The dropped_frames counter is only a lower bound on the actual
|
|
||||||
number of dropped frames, with the special case that if dropped_frames |
|
||||||
is zero, then it is guaranteed that NO frames have been dropped |
|
||||||
since the last call to DV1394_GET_STATUS. |
|
||||||
*/ |
|
||||||
}; |
|
||||||
|
|
||||||
|
|
||||||
#endif /* AVDEVICE_DV1394_H */ |
|
||||||
Loading…
Reference in new issue