[FFmpeg-devel] lavd: remove deprecated dv1394 device

Josh de Kock josh at itanimul.li
Wed Sep 27 15:09:02 EEST 2017


Support for this device has been removed in kernel since v2.6.37. dv1394
has been superseded by libiec61883 which is functionally equivalent.

Signed-off-by: Josh de Kock <josh at itanimul.li>
---
 configure                |   3 -
 doc/indevs.texi          |  25 ----
 libavdevice/Makefile     |   1 -
 libavdevice/alldevices.c |   1 -
 libavdevice/dv1394.c     | 239 -------------------------------
 libavdevice/dv1394.h     | 357
-----------------------------------------------
 6 files changed, 626 deletions(-)
 delete mode 100644 libavdevice/dv1394.c
 delete mode 100644 libavdevice/dv1394.h

diff --git a/configure b/configure
index ba38a73906..a645ff4959 100755
--- a/configure
+++ b/configure
@@ -3075,8 +3075,6 @@ libndi_newtek_outdev_deps="libndi_newtek"
 libndi_newtek_outdev_extralibs="-lndi"
 dshow_indev_deps="IBaseFilter"
 dshow_indev_extralibs="-lpsapi -lole32 -lstrmiids -luuid -loleaut32
-lshlwapi"
-dv1394_indev_deps="dv1394"
-dv1394_indev_select="dv_demuxer"
 fbdev_indev_deps="linux_fb_h"
 fbdev_outdev_deps="linux_fb_h"
 gdigrab_indev_deps="CreateDIBSection"
@@ -5068,7 +5066,6 @@ case $target_os in
         add_cppflags -U__STRICT_ANSI__
         ;;
     linux)
-        enable dv1394
         enable section_data_rel_ro
         enabled_any arm aarch64 && enable_weak linux_perf
         ;;
diff --git a/doc/indevs.texi b/doc/indevs.texi
index 30b7ac2380..776e563160 100644
--- a/doc/indevs.texi
+++ b/doc/indevs.texi
@@ -641,31 +641,6 @@ $ ffmpeg -f dshow -show_video_device_dialog true
-crossbar_video_input_pin_numbe

 @end itemize

- at section dv1394
-
-Linux DV 1394 input device.
-
- at subsection Options
-
- at table @option
-
- at item framerate
-Set the frame rate. Default is 25.
-
- at item standard
-
-Available values are:
- at table @samp
- at item pal
-
- at item ntsc
-
- at end table
-
-Default value is @code{ntsc}.
-
- at end table
-
 @section fbdev

 Linux framebuffer input device.
diff --git a/libavdevice/Makefile b/libavdevice/Makefile
index f40f4d5298..8228d62147 100644
--- a/libavdevice/Makefile
+++ b/libavdevice/Makefile
@@ -24,7 +24,6 @@ OBJS-$(CONFIG_LIBNDI_NEWTEK_INDEV)       +=
libndi_newtek_dec.o
 OBJS-$(CONFIG_DSHOW_INDEV)               += dshow_crossbar.o dshow.o
dshow_enummediatypes.o \
                                             dshow_enumpins.o
dshow_filter.o \
                                             dshow_pin.o dshow_common.o
-OBJS-$(CONFIG_DV1394_INDEV)              += dv1394.o
 OBJS-$(CONFIG_FBDEV_INDEV)               += fbdev_dec.o \
                                             fbdev_common.o
 OBJS-$(CONFIG_FBDEV_OUTDEV)              += fbdev_enc.o \
diff --git a/libavdevice/alldevices.c b/libavdevice/alldevices.c
index b31558bcb5..b767b6a718 100644
--- a/libavdevice/alldevices.c
+++ b/libavdevice/alldevices.c
@@ -48,7 +48,6 @@ static void register_all(void)
     REGISTER_INOUTDEV(DECKLINK,         decklink);
     REGISTER_INOUTDEV(LIBNDI_NEWTEK,    libndi_newtek);
     REGISTER_INDEV   (DSHOW,            dshow);
-    REGISTER_INDEV   (DV1394,           dv1394);
     REGISTER_INOUTDEV(FBDEV,            fbdev);
     REGISTER_INDEV   (GDIGRAB,          gdigrab);
     REGISTER_INDEV   (IEC61883,         iec61883);
diff --git a/libavdevice/dv1394.c b/libavdevice/dv1394.c
deleted file mode 100644
index c3483010fa..0000000000
--- a/libavdevice/dv1394.c
+++ /dev/null
@@ -1,239 +0,0 @@
-/*
- * Linux DV1394 interface
- * Copyright (c) 2003 Max Krasnyansky <maxk at qualcomm.com>
- *
- * 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
- */
-
-#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 "avdevice.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. Resetting ..\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). Resetting ..\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, -1);
-    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_freep(&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,
-    .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
-};
-
-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,
-};
diff --git a/libavdevice/dv1394.h b/libavdevice/dv1394.h
deleted file mode 100644
index b76d633ef6..0000000000
--- a/libavdevice/dv1394.h
+++ /dev/null
@@ -1,357 +0,0 @@
-/*
- * DV input/output over IEEE 1394 on OHCI chips
- *   Copyright (C)2001 Daniel Maas <dmaas at dcine.com>
- *     receive, proc_fs by Dan Dennedy <dan at dennedy.org>
- *
- * based on:
- *   video1394.h - driver for OHCI 1394 boards
- *   Copyright (C)1999,2000 Sebastien Rougeaux
<sebastien.rougeaux at anu.edu.au>
- *                          Peter Schlaile <udbz at rz.uni-karlsruhe.de>
- *
- * 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
- */
-
-#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 */
-- 
2.11.0 (Apple Git-81)



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