1/*
2 * Linux DV1394 interface
3 * Copyright (c) 2003 Max Krasnyansky <maxk@qualcomm.com>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include "config.h"
23#include <unistd.h>
24#include <fcntl.h>
25#include <errno.h>
26#include <poll.h>
27#include <sys/ioctl.h>
28#include <sys/mman.h>
29
30#include "libavutil/internal.h"
31#include "libavutil/log.h"
32#include "libavutil/opt.h"
33#include "avdevice.h"
34#include "libavformat/dv.h"
35#include "dv1394.h"
36
37struct dv1394_data {
38    AVClass *class;
39    int fd;
40    int channel;
41    int format;
42
43    uint8_t *ring; /* Ring buffer */
44    int index;  /* Current frame index */
45    int avail;  /* Number of frames available for reading */
46    int done;   /* Number of completed frames */
47
48    DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */
49};
50
51/*
52 * The trick here is to kludge around well known problem with kernel Ooopsing
53 * when you try to capture PAL on a device node configure for NTSC. That's
54 * why we have to configure the device node for PAL, and then read only NTSC
55 * amount of data.
56 */
57static int dv1394_reset(struct dv1394_data *dv)
58{
59    struct dv1394_init init;
60
61    init.channel     = dv->channel;
62    init.api_version = DV1394_API_VERSION;
63    init.n_frames    = DV1394_RING_FRAMES;
64    init.format      = DV1394_PAL;
65
66    if (ioctl(dv->fd, DV1394_INIT, &init) < 0)
67        return -1;
68
69    dv->avail  = dv->done = 0;
70    return 0;
71}
72
73static int dv1394_start(struct dv1394_data *dv)
74{
75    /* Tell DV1394 driver to enable receiver */
76    if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) {
77        av_log(NULL, AV_LOG_ERROR, "Failed to start receiver: %s\n", strerror(errno));
78        return -1;
79    }
80    return 0;
81}
82
83static int dv1394_read_header(AVFormatContext * context)
84{
85    struct dv1394_data *dv = context->priv_data;
86
87    dv->dv_demux = avpriv_dv_init_demux(context);
88    if (!dv->dv_demux)
89        goto failed;
90
91    /* Open and initialize DV1394 device */
92    dv->fd = avpriv_open(context->filename, O_RDONLY);
93    if (dv->fd < 0) {
94        av_log(context, AV_LOG_ERROR, "Failed to open DV interface: %s\n", strerror(errno));
95        goto failed;
96    }
97
98    if (dv1394_reset(dv) < 0) {
99        av_log(context, AV_LOG_ERROR, "Failed to initialize DV interface: %s\n", strerror(errno));
100        goto failed;
101    }
102
103    dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES,
104                    PROT_READ, MAP_PRIVATE, dv->fd, 0);
105    if (dv->ring == MAP_FAILED) {
106        av_log(context, AV_LOG_ERROR, "Failed to mmap DV ring buffer: %s\n", strerror(errno));
107        goto failed;
108    }
109
110    if (dv1394_start(dv) < 0)
111        goto failed;
112
113    return 0;
114
115failed:
116    close(dv->fd);
117    return AVERROR(EIO);
118}
119
120static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
121{
122    struct dv1394_data *dv = context->priv_data;
123    int size;
124
125    size = avpriv_dv_get_packet(dv->dv_demux, pkt);
126    if (size > 0)
127        return size;
128
129    if (!dv->avail) {
130        struct dv1394_status s;
131        struct pollfd p;
132
133        if (dv->done) {
134            /* Request more frames */
135            if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
136                /* This usually means that ring buffer overflowed.
137                 * We have to reset :(.
138                 */
139
140                av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");
141
142                dv1394_reset(dv);
143                dv1394_start(dv);
144            }
145            dv->done = 0;
146        }
147
148        /* Wait until more frames are available */
149restart_poll:
150        p.fd = dv->fd;
151        p.events = POLLIN | POLLERR | POLLHUP;
152        if (poll(&p, 1, -1) < 0) {
153            if (errno == EAGAIN || errno == EINTR)
154                goto restart_poll;
155            av_log(context, AV_LOG_ERROR, "Poll failed: %s\n", strerror(errno));
156            return AVERROR(EIO);
157        }
158
159        if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {
160            av_log(context, AV_LOG_ERROR, "Failed to get status: %s\n", strerror(errno));
161            return AVERROR(EIO);
162        }
163        av_dlog(context, "DV1394: status\n"
164                "\tactive_frame\t%d\n"
165                "\tfirst_clear_frame\t%d\n"
166                "\tn_clear_frames\t%d\n"
167                "\tdropped_frames\t%d\n",
168                s.active_frame, s.first_clear_frame,
169                s.n_clear_frames, s.dropped_frames);
170
171        dv->avail = s.n_clear_frames;
172        dv->index = s.first_clear_frame;
173        dv->done  = 0;
174
175        if (s.dropped_frames) {
176            av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",
177                    s.dropped_frames);
178
179            dv1394_reset(dv);
180            dv1394_start(dv);
181        }
182    }
183
184    av_dlog(context, "index %d, avail %d, done %d\n", dv->index, dv->avail,
185            dv->done);
186
187    size = avpriv_dv_produce_packet(dv->dv_demux, pkt,
188                             dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE),
189                             DV1394_PAL_FRAME_SIZE, -1);
190    dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
191    dv->done++; dv->avail--;
192
193    return size;
194}
195
196static int dv1394_close(AVFormatContext * context)
197{
198    struct dv1394_data *dv = context->priv_data;
199
200    /* Shutdown DV1394 receiver */
201    if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)
202        av_log(context, AV_LOG_ERROR, "Failed to shutdown DV1394: %s\n", strerror(errno));
203
204    /* Unmap ring buffer */
205    if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)
206        av_log(context, AV_LOG_ERROR, "Failed to munmap DV1394 ring buffer: %s\n", strerror(errno));
207
208    close(dv->fd);
209    av_free(dv->dv_demux);
210
211    return 0;
212}
213
214static const AVOption options[] = {
215    { "standard", "", offsetof(struct dv1394_data, format), AV_OPT_TYPE_INT, {.i64 = DV1394_NTSC}, DV1394_NTSC, DV1394_PAL, AV_OPT_FLAG_DECODING_PARAM, "standard" },
216    { "PAL",      "", 0, AV_OPT_TYPE_CONST, {.i64 = DV1394_PAL},   0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
217    { "NTSC",     "", 0, AV_OPT_TYPE_CONST, {.i64 = DV1394_NTSC},  0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
218    { "channel",  "", offsetof(struct dv1394_data, channel), AV_OPT_TYPE_INT, {.i64 = DV1394_DEFAULT_CHANNEL}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
219    { NULL },
220};
221
222static const AVClass dv1394_class = {
223    .class_name = "DV1394 indev",
224    .item_name  = av_default_item_name,
225    .option     = options,
226    .version    = LIBAVUTIL_VERSION_INT,
227    .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
228};
229
230AVInputFormat ff_dv1394_demuxer = {
231    .name           = "dv1394",
232    .long_name      = NULL_IF_CONFIG_SMALL("DV1394 A/V grab"),
233    .priv_data_size = sizeof(struct dv1394_data),
234    .read_header    = dv1394_read_header,
235    .read_packet    = dv1394_read_packet,
236    .read_close     = dv1394_close,
237    .flags          = AVFMT_NOFILE,
238    .priv_class     = &dv1394_class,
239};
240