1 /*
2 * V4L2 mem2mem decoders
3 *
4 * Copyright (C) 2017 Alexis Ballier <aballier@gentoo.org>
5 * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz@linaro.org>
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 #include <linux/videodev2.h>
25 #include <sys/ioctl.h>
26 #include "libavutil/pixfmt.h"
27 #include "libavutil/pixdesc.h"
28 #include "libavutil/opt.h"
29 #include "libavcodec/avcodec.h"
30 #include "libavcodec/decode.h"
31 #include "libavcodec/internal.h"
32
33 #include "v4l2_context.h"
34 #include "v4l2_m2m.h"
35 #include "v4l2_fmt.h"
36
v4l2_try_start(AVCodecContext * avctx)37 static int v4l2_try_start(AVCodecContext *avctx)
38 {
39 V4L2m2mContext *s = ((V4L2m2mPriv*)avctx->priv_data)->context;
40 V4L2Context *const capture = &s->capture;
41 V4L2Context *const output = &s->output;
42 struct v4l2_selection selection = { 0 };
43 int ret;
44
45 /* 1. start the output process */
46 if (!output->streamon) {
47 ret = ff_v4l2_context_set_status(output, VIDIOC_STREAMON);
48 if (ret < 0) {
49 av_log(avctx, AV_LOG_DEBUG, "VIDIOC_STREAMON on output context\n");
50 return ret;
51 }
52 }
53
54 if (capture->streamon)
55 return 0;
56
57 /* 2. get the capture format */
58 capture->format.type = capture->type;
59 ret = ioctl(s->fd, VIDIOC_G_FMT, &capture->format);
60 if (ret) {
61 av_log(avctx, AV_LOG_WARNING, "VIDIOC_G_FMT ioctl\n");
62 return ret;
63 }
64
65 /* 2.1 update the AVCodecContext */
66 avctx->pix_fmt = ff_v4l2_format_v4l2_to_avfmt(capture->format.fmt.pix_mp.pixelformat, AV_CODEC_ID_RAWVIDEO);
67 capture->av_pix_fmt = avctx->pix_fmt;
68
69 /* 3. set the crop parameters */
70 selection.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
71 selection.r.height = avctx->coded_height;
72 selection.r.width = avctx->coded_width;
73 ret = ioctl(s->fd, VIDIOC_S_SELECTION, &selection);
74 if (!ret) {
75 ret = ioctl(s->fd, VIDIOC_G_SELECTION, &selection);
76 if (ret) {
77 av_log(avctx, AV_LOG_WARNING, "VIDIOC_G_SELECTION ioctl\n");
78 } else {
79 av_log(avctx, AV_LOG_DEBUG, "crop output %dx%d\n", selection.r.width, selection.r.height);
80 /* update the size of the resulting frame */
81 capture->height = selection.r.height;
82 capture->width = selection.r.width;
83 }
84 }
85
86 /* 4. init the capture context now that we have the capture format */
87 if (!capture->buffers) {
88 ret = ff_v4l2_context_init(capture);
89 if (ret) {
90 av_log(avctx, AV_LOG_ERROR, "can't request capture buffers\n");
91 return AVERROR(ENOMEM);
92 }
93 }
94
95 /* 5. start the capture process */
96 ret = ff_v4l2_context_set_status(capture, VIDIOC_STREAMON);
97 if (ret) {
98 av_log(avctx, AV_LOG_DEBUG, "VIDIOC_STREAMON, on capture context\n");
99 return ret;
100 }
101
102 return 0;
103 }
104
v4l2_prepare_decoder(V4L2m2mContext * s)105 static int v4l2_prepare_decoder(V4L2m2mContext *s)
106 {
107 struct v4l2_event_subscription sub;
108 V4L2Context *output = &s->output;
109 int ret;
110
111 /**
112 * requirements
113 */
114 memset(&sub, 0, sizeof(sub));
115 sub.type = V4L2_EVENT_SOURCE_CHANGE;
116 ret = ioctl(s->fd, VIDIOC_SUBSCRIBE_EVENT, &sub);
117 if ( ret < 0) {
118 if (output->height == 0 || output->width == 0) {
119 av_log(s->avctx, AV_LOG_ERROR,
120 "the v4l2 driver does not support VIDIOC_SUBSCRIBE_EVENT\n"
121 "you must provide codec_height and codec_width on input\n");
122 return ret;
123 }
124 }
125
126 memset(&sub, 0, sizeof(sub));
127 sub.type = V4L2_EVENT_EOS;
128 ret = ioctl(s->fd, VIDIOC_SUBSCRIBE_EVENT, &sub);
129 if (ret < 0)
130 av_log(s->avctx, AV_LOG_WARNING,
131 "the v4l2 driver does not support end of stream VIDIOC_SUBSCRIBE_EVENT\n");
132
133 return 0;
134 }
135
v4l2_receive_frame(AVCodecContext * avctx,AVFrame * frame)136 static int v4l2_receive_frame(AVCodecContext *avctx, AVFrame *frame)
137 {
138 V4L2m2mContext *s = ((V4L2m2mPriv*)avctx->priv_data)->context;
139 V4L2Context *const capture = &s->capture;
140 V4L2Context *const output = &s->output;
141 int ret;
142
143 if (!s->buf_pkt.size) {
144 ret = ff_decode_get_packet(avctx, &s->buf_pkt);
145 if (ret < 0 && ret != AVERROR_EOF)
146 return ret;
147 }
148
149 if (s->draining)
150 goto dequeue;
151
152 ret = ff_v4l2_context_enqueue_packet(output, &s->buf_pkt);
153 if (ret < 0 && ret != AVERROR(EAGAIN))
154 goto fail;
155
156 /* if EAGAIN don't unref packet and try to enqueue in the next iteration */
157 if (ret != AVERROR(EAGAIN))
158 av_packet_unref(&s->buf_pkt);
159
160 if (!s->draining) {
161 ret = v4l2_try_start(avctx);
162 if (ret) {
163 /* cant recover */
164 if (ret != AVERROR(ENOMEM))
165 ret = 0;
166 goto fail;
167 }
168 }
169
170 dequeue:
171 return ff_v4l2_context_dequeue_frame(capture, frame, -1);
172 fail:
173 av_packet_unref(&s->buf_pkt);
174 return ret;
175 }
176
v4l2_decode_init(AVCodecContext * avctx)177 static av_cold int v4l2_decode_init(AVCodecContext *avctx)
178 {
179 V4L2Context *capture, *output;
180 V4L2m2mContext *s;
181 V4L2m2mPriv *priv = avctx->priv_data;
182 int ret;
183
184 ret = ff_v4l2_m2m_create_context(priv, &s);
185 if (ret < 0)
186 return ret;
187
188 capture = &s->capture;
189 output = &s->output;
190
191 /* if these dimensions are invalid (ie, 0 or too small) an event will be raised
192 * by the v4l2 driver; this event will trigger a full pipeline reconfig and
193 * the proper values will be retrieved from the kernel driver.
194 */
195 output->height = capture->height = avctx->coded_height;
196 output->width = capture->width = avctx->coded_width;
197
198 output->av_codec_id = avctx->codec_id;
199 output->av_pix_fmt = AV_PIX_FMT_NONE;
200
201 capture->av_codec_id = AV_CODEC_ID_RAWVIDEO;
202 capture->av_pix_fmt = avctx->pix_fmt;
203
204 s->avctx = avctx;
205 ret = ff_v4l2_m2m_codec_init(priv);
206 if (ret) {
207 av_log(avctx, AV_LOG_ERROR, "can't configure decoder\n");
208 return ret;
209 }
210
211 return v4l2_prepare_decoder(s);
212 }
213
v4l2_decode_close(AVCodecContext * avctx)214 static av_cold int v4l2_decode_close(AVCodecContext *avctx)
215 {
216 return ff_v4l2_m2m_codec_end(avctx->priv_data);
217 }
218
219 #define OFFSET(x) offsetof(V4L2m2mPriv, x)
220 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_DECODING_PARAM
221
222 static const AVOption options[] = {
223 V4L_M2M_DEFAULT_OPTS,
224 { "num_capture_buffers", "Number of buffers in the capture context",
225 OFFSET(num_capture_buffers), AV_OPT_TYPE_INT, {.i64 = 20}, 20, INT_MAX, FLAGS },
226 { NULL},
227 };
228
229 #define M2MDEC_CLASS(NAME) \
230 static const AVClass v4l2_m2m_ ## NAME ## _dec_class = { \
231 .class_name = #NAME "_v4l2m2m_decoder", \
232 .item_name = av_default_item_name, \
233 .option = options, \
234 .version = LIBAVUTIL_VERSION_INT, \
235 };
236
237 #define M2MDEC(NAME, LONGNAME, CODEC, bsf_name) \
238 M2MDEC_CLASS(NAME) \
239 AVCodec ff_ ## NAME ## _v4l2m2m_decoder = { \
240 .name = #NAME "_v4l2m2m" , \
241 .long_name = NULL_IF_CONFIG_SMALL("V4L2 mem2mem " LONGNAME " decoder wrapper"), \
242 .type = AVMEDIA_TYPE_VIDEO, \
243 .id = CODEC , \
244 .priv_data_size = sizeof(V4L2m2mPriv), \
245 .priv_class = &v4l2_m2m_ ## NAME ## _dec_class, \
246 .init = v4l2_decode_init, \
247 .receive_frame = v4l2_receive_frame, \
248 .close = v4l2_decode_close, \
249 .bsfs = bsf_name, \
250 .capabilities = AV_CODEC_CAP_HARDWARE | AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AVOID_PROBING, \
251 .caps_internal = FF_CODEC_CAP_SETS_PKT_DTS | FF_CODEC_CAP_INIT_CLEANUP, \
252 .wrapper_name = "v4l2m2m", \
253 }
254
255 M2MDEC(h264, "H.264", AV_CODEC_ID_H264, "h264_mp4toannexb");
256 M2MDEC(hevc, "HEVC", AV_CODEC_ID_HEVC, "hevc_mp4toannexb");
257 M2MDEC(mpeg1, "MPEG1", AV_CODEC_ID_MPEG1VIDEO, NULL);
258 M2MDEC(mpeg2, "MPEG2", AV_CODEC_ID_MPEG2VIDEO, NULL);
259 M2MDEC(mpeg4, "MPEG4", AV_CODEC_ID_MPEG4, NULL);
260 M2MDEC(h263, "H.263", AV_CODEC_ID_H263, NULL);
261 M2MDEC(vc1 , "VC1", AV_CODEC_ID_VC1, NULL);
262 M2MDEC(vp8, "VP8", AV_CODEC_ID_VP8, NULL);
263 M2MDEC(vp9, "VP9", AV_CODEC_ID_VP9, NULL);
264