FFmpeg coverage

GCC Code Coverage Report

Directory:	../../../ffmpeg/		Exec	Total	Coverage
File:	src/libavcodec/v4l2_m2m.c	Lines:	0	228	0.0 %
Date:	2021-04-22 14:24:15	Branches:	0	122	0.0 %


/*
 * V4L mem2mem
 *
 * Copyright (C) 2017 Alexis Ballier <aballier@gentoo.org>
 * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz@linaro.org>
 *
 * 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 <linux/videodev2.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <unistd.h>
#include <dirent.h>
#include <fcntl.h>
#include "libavcodec/avcodec.h"
#include "libavcodec/internal.h"
#include "libavutil/pixdesc.h"
#include "libavutil/imgutils.h"
#include "libavutil/pixfmt.h"
#include "v4l2_context.h"
#include "v4l2_fmt.h"
#include "v4l2_m2m.h"

static inline int v4l2_splane_video(struct v4l2_capability *cap)
{
    if (cap->capabilities & (V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_VIDEO_OUTPUT) &&
        cap->capabilities & V4L2_CAP_STREAMING)
        return 1;

    if (cap->capabilities & V4L2_CAP_VIDEO_M2M)
        return 1;

    return 0;
}

static inline int v4l2_mplane_video(struct v4l2_capability *cap)
{
    if (cap->capabilities & (V4L2_CAP_VIDEO_CAPTURE_MPLANE | V4L2_CAP_VIDEO_OUTPUT_MPLANE) &&
        cap->capabilities & V4L2_CAP_STREAMING)
        return 1;

    if (cap->capabilities & V4L2_CAP_VIDEO_M2M_MPLANE)
        return 1;

    return 0;
}

static int v4l2_prepare_contexts(V4L2m2mContext *s, int probe)
{
    struct v4l2_capability cap;
    void *log_ctx = s->avctx;
    int ret;

    s->capture.done = s->output.done = 0;
    s->capture.name = "capture";
    s->output.name = "output";
    atomic_init(&s->refcount, 0);
    sem_init(&s->refsync, 0, 0);

    memset(&cap, 0, sizeof(cap));
    ret = ioctl(s->fd, VIDIOC_QUERYCAP, &cap);
    if (ret < 0)
        return ret;

    av_log(log_ctx, probe ? AV_LOG_DEBUG : AV_LOG_INFO,
                     "driver '%s' on card '%s' in %s mode\n", cap.driver, cap.card,
                     v4l2_mplane_video(&cap) ? "mplane" :
                     v4l2_splane_video(&cap) ? "splane" : "unknown");

    if (v4l2_mplane_video(&cap)) {
        s->capture.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
        s->output.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
        return 0;
    }

    if (v4l2_splane_video(&cap)) {
        s->capture.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        s->output.type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
        return 0;
    }

    return AVERROR(EINVAL);
}

static int v4l2_probe_driver(V4L2m2mContext *s)
{
    void *log_ctx = s->avctx;
    int ret;

    s->fd = open(s->devname, O_RDWR | O_NONBLOCK, 0);
    if (s->fd < 0)
        return AVERROR(errno);

    ret = v4l2_prepare_contexts(s, 1);
    if (ret < 0)
        goto done;

    ret = ff_v4l2_context_get_format(&s->output, 1);
    if (ret) {
        av_log(log_ctx, AV_LOG_DEBUG, "v4l2 output format not supported\n");
        goto done;
    }

    ret = ff_v4l2_context_get_format(&s->capture, 1);
    if (ret) {
        av_log(log_ctx, AV_LOG_DEBUG, "v4l2 capture format not supported\n");
        goto done;
    }

done:
    if (close(s->fd) < 0) {
        ret = AVERROR(errno);
        av_log(log_ctx, AV_LOG_ERROR, "failure closing %s (%s)\n", s->devname, av_err2str(AVERROR(errno)));
    }

    s->fd = -1;

    return ret;
}

static int v4l2_configure_contexts(V4L2m2mContext *s)
{
    void *log_ctx = s->avctx;
    int ret;
    struct v4l2_format ofmt, cfmt;

    s->fd = open(s->devname, O_RDWR | O_NONBLOCK, 0);
    if (s->fd < 0)
        return AVERROR(errno);

    ret = v4l2_prepare_contexts(s, 0);
    if (ret < 0)
        goto error;

    ofmt = s->output.format;
    cfmt = s->capture.format;
    av_log(log_ctx, AV_LOG_INFO, "requesting formats: output=%s capture=%s\n",
                                 av_fourcc2str(V4L2_TYPE_IS_MULTIPLANAR(ofmt.type) ?
                                               ofmt.fmt.pix_mp.pixelformat :
                                               ofmt.fmt.pix.pixelformat),
                                 av_fourcc2str(V4L2_TYPE_IS_MULTIPLANAR(cfmt.type) ?
                                               cfmt.fmt.pix_mp.pixelformat :
                                               cfmt.fmt.pix.pixelformat));

    ret = ff_v4l2_context_set_format(&s->output);
    if (ret) {
        av_log(log_ctx, AV_LOG_ERROR, "can't set v4l2 output format\n");
        goto error;
    }

    ret = ff_v4l2_context_set_format(&s->capture);
    if (ret) {
        av_log(log_ctx, AV_LOG_ERROR, "can't to set v4l2 capture format\n");
        goto error;
    }

    ret = ff_v4l2_context_init(&s->output);
    if (ret) {
        av_log(log_ctx, AV_LOG_ERROR, "no v4l2 output context's buffers\n");
        goto error;
    }

    /* decoder's buffers need to be updated at a later stage */
    if (s->avctx && !av_codec_is_decoder(s->avctx->codec)) {
        ret = ff_v4l2_context_init(&s->capture);
        if (ret) {
            av_log(log_ctx, AV_LOG_ERROR, "no v4l2 capture context's buffers\n");
            goto error;
        }
    }

    return 0;

error:
    if (close(s->fd) < 0) {
        ret = AVERROR(errno);
        av_log(log_ctx, AV_LOG_ERROR, "error closing %s (%s)\n",
            s->devname, av_err2str(AVERROR(errno)));
    }
    s->fd = -1;

    return ret;
}

/******************************************************************************
 *
 *                  V4L2 M2M Interface
 *
 ******************************************************************************/
int ff_v4l2_m2m_codec_reinit(V4L2m2mContext *s)
{
    void *log_ctx = s->avctx;
    int ret;

    av_log(log_ctx, AV_LOG_DEBUG, "reinit context\n");

    /* 1. streamoff */
    ret = ff_v4l2_context_set_status(&s->capture, VIDIOC_STREAMOFF);
    if (ret)
        av_log(log_ctx, AV_LOG_ERROR, "capture VIDIOC_STREAMOFF\n");

    /* 2. unmap the capture buffers (v4l2 and ffmpeg):
     *    we must wait for all references to be released before being allowed
     *    to queue new buffers.
     */
    av_log(log_ctx, AV_LOG_DEBUG, "waiting for user to release AVBufferRefs\n");
    if (atomic_load(&s->refcount))
        while(sem_wait(&s->refsync) == -1 && errno == EINTR);

    ff_v4l2_context_release(&s->capture);

    /* 3. get the new capture format */
    ret = ff_v4l2_context_get_format(&s->capture, 0);
    if (ret) {
        av_log(log_ctx, AV_LOG_ERROR, "query the new capture format\n");
        return ret;
    }

    /* 4. set the capture format */
    ret = ff_v4l2_context_set_format(&s->capture);
    if (ret) {
        av_log(log_ctx, AV_LOG_ERROR, "setting capture format\n");
        return ret;
    }

    /* 5. complete reinit */
    s->draining = 0;
    s->reinit = 0;

    return 0;
}

int ff_v4l2_m2m_codec_full_reinit(V4L2m2mContext *s)
{
    void *log_ctx = s->avctx;
    int ret;

    av_log(log_ctx, AV_LOG_DEBUG, "%s full reinit\n", s->devname);

    /* wait for pending buffer references */
    if (atomic_load(&s->refcount))
        while(sem_wait(&s->refsync) == -1 && errno == EINTR);

    ret = ff_v4l2_context_set_status(&s->output, VIDIOC_STREAMOFF);
    if (ret) {
        av_log(log_ctx, AV_LOG_ERROR, "output VIDIOC_STREAMOFF\n");
        goto error;
    }

    ret = ff_v4l2_context_set_status(&s->capture, VIDIOC_STREAMOFF);
    if (ret) {
        av_log(log_ctx, AV_LOG_ERROR, "capture VIDIOC_STREAMOFF\n");
        goto error;
    }

    /* release and unmmap the buffers */
    ff_v4l2_context_release(&s->output);
    ff_v4l2_context_release(&s->capture);

    /* start again now that we know the stream dimensions */
    s->draining = 0;
    s->reinit = 0;

    ret = ff_v4l2_context_get_format(&s->output, 0);
    if (ret) {
        av_log(log_ctx, AV_LOG_DEBUG, "v4l2 output format not supported\n");
        goto error;
    }

    ret = ff_v4l2_context_get_format(&s->capture, 0);
    if (ret) {
        av_log(log_ctx, AV_LOG_DEBUG, "v4l2 capture format not supported\n");
        goto error;
    }

    ret = ff_v4l2_context_set_format(&s->output);
    if (ret) {
        av_log(log_ctx, AV_LOG_ERROR, "can't set v4l2 output format\n");
        goto error;
    }

    ret = ff_v4l2_context_set_format(&s->capture);
    if (ret) {
        av_log(log_ctx, AV_LOG_ERROR, "can't to set v4l2 capture format\n");
        goto error;
    }

    ret = ff_v4l2_context_init(&s->output);
    if (ret) {
        av_log(log_ctx, AV_LOG_ERROR, "no v4l2 output context's buffers\n");
        goto error;
    }

    /* decoder's buffers need to be updated at a later stage */
    if (s->avctx && !av_codec_is_decoder(s->avctx->codec)) {
        ret = ff_v4l2_context_init(&s->capture);
        if (ret) {
            av_log(log_ctx, AV_LOG_ERROR, "no v4l2 capture context's buffers\n");
            goto error;
        }
    }

    return 0;

error:
    return ret;
}

static void v4l2_m2m_destroy_context(void *opaque, uint8_t *context)
{
    V4L2m2mContext *s = (V4L2m2mContext*)context;

    ff_v4l2_context_release(&s->capture);
    sem_destroy(&s->refsync);

    close(s->fd);
    av_frame_unref(s->frame);
    av_frame_free(&s->frame);
    av_packet_unref(&s->buf_pkt);

    av_free(s);
}

int ff_v4l2_m2m_codec_end(V4L2m2mPriv *priv)
{
    V4L2m2mContext *s = priv->context;
    int ret;

    if (!s)
        return 0;

    if (s->fd >= 0) {
        ret = ff_v4l2_context_set_status(&s->output, VIDIOC_STREAMOFF);
        if (ret)
            av_log(s->avctx, AV_LOG_ERROR, "VIDIOC_STREAMOFF %s\n", s->output.name);

        ret = ff_v4l2_context_set_status(&s->capture, VIDIOC_STREAMOFF);
        if (ret)
            av_log(s->avctx, AV_LOG_ERROR, "VIDIOC_STREAMOFF %s\n", s->capture.name);
    }

    ff_v4l2_context_release(&s->output);

    s->self_ref = NULL;
    av_buffer_unref(&priv->context_ref);

    return 0;
}

int ff_v4l2_m2m_codec_init(V4L2m2mPriv *priv)
{
    int ret = AVERROR(EINVAL);
    struct dirent *entry;
    DIR *dirp;

    V4L2m2mContext *s = priv->context;

    dirp = opendir("/dev");
    if (!dirp)
        return AVERROR(errno);

    for (entry = readdir(dirp); entry; entry = readdir(dirp)) {

        if (strncmp(entry->d_name, "video", 5))
            continue;

        snprintf(s->devname, sizeof(s->devname), "/dev/%s", entry->d_name);
        av_log(s->avctx, AV_LOG_DEBUG, "probing device %s\n", s->devname);
        ret = v4l2_probe_driver(s);
        if (!ret)
            break;
    }

    closedir(dirp);

    if (ret) {
        av_log(s->avctx, AV_LOG_ERROR, "Could not find a valid device\n");
        memset(s->devname, 0, sizeof(s->devname));

        return ret;
    }

    av_log(s->avctx, AV_LOG_INFO, "Using device %s\n", s->devname);

    return v4l2_configure_contexts(s);
}

int ff_v4l2_m2m_create_context(V4L2m2mPriv *priv, V4L2m2mContext **s)
{
    *s = av_mallocz(sizeof(V4L2m2mContext));
    if (!*s)
        return AVERROR(ENOMEM);

    priv->context_ref = av_buffer_create((uint8_t *) *s, sizeof(V4L2m2mContext),
                                         &v4l2_m2m_destroy_context, NULL, 0);
    if (!priv->context_ref) {
        av_freep(s);
        return AVERROR(ENOMEM);
    }

    /* assign the context */
    priv->context = *s;
    (*s)->priv = priv;

    /* populate it */
    priv->context->capture.num_buffers = priv->num_capture_buffers;
    priv->context->output.num_buffers  = priv->num_output_buffers;
    priv->context->self_ref = priv->context_ref;
    priv->context->fd = -1;

    priv->context->frame = av_frame_alloc();
    if (!priv->context->frame) {
        av_buffer_unref(&priv->context_ref);
        *s = NULL; /* freed when unreferencing context_ref */
        return AVERROR(ENOMEM);
    }

    return 0;
}


Generated by: GCOVR (Version 4.2)

Line	Branch	Exec	Source
1			/*
2			* V4L mem2mem
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 <sys/mman.h>
27			#include <unistd.h>
28			#include <dirent.h>
29			#include <fcntl.h>
30			#include "libavcodec/avcodec.h"
31			#include "libavcodec/internal.h"
32			#include "libavutil/pixdesc.h"
33			#include "libavutil/imgutils.h"
34			#include "libavutil/pixfmt.h"
35			#include "v4l2_context.h"
36			#include "v4l2_fmt.h"
37			#include "v4l2_m2m.h"
38
39			static inline int v4l2_splane_video(struct v4l2_capability *cap)
40			{
41			if (cap->capabilities & (V4L2_CAP_VIDEO_CAPTURE \| V4L2_CAP_VIDEO_OUTPUT) &&
42			cap->capabilities & V4L2_CAP_STREAMING)
43			return 1;
44
45			if (cap->capabilities & V4L2_CAP_VIDEO_M2M)
46			return 1;
47
48			return 0;
49			}
50
51			static inline int v4l2_mplane_video(struct v4l2_capability *cap)
52			{
53			if (cap->capabilities & (V4L2_CAP_VIDEO_CAPTURE_MPLANE \| V4L2_CAP_VIDEO_OUTPUT_MPLANE) &&
54			cap->capabilities & V4L2_CAP_STREAMING)
55			return 1;
56
57			if (cap->capabilities & V4L2_CAP_VIDEO_M2M_MPLANE)
58			return 1;
59
60			return 0;
61			}
62
63			static int v4l2_prepare_contexts(V4L2m2mContext *s, int probe)
64			{
65			struct v4l2_capability cap;
66			void *log_ctx = s->avctx;
67			int ret;
68
69			s->capture.done = s->output.done = 0;
70			s->capture.name = "capture";
71			s->output.name = "output";
72			atomic_init(&s->refcount, 0);
73			sem_init(&s->refsync, 0, 0);
74
75			memset(&cap, 0, sizeof(cap));
76			ret = ioctl(s->fd, VIDIOC_QUERYCAP, &cap);
77			if (ret < 0)
78			return ret;
79
80			av_log(log_ctx, probe ? AV_LOG_DEBUG : AV_LOG_INFO,
81			"driver '%s' on card '%s' in %s mode\n", cap.driver, cap.card,
82			v4l2_mplane_video(&cap) ? "mplane" :
83			v4l2_splane_video(&cap) ? "splane" : "unknown");
84
85			if (v4l2_mplane_video(&cap)) {
86			s->capture.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
87			s->output.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
88			return 0;
89			}
90
91			if (v4l2_splane_video(&cap)) {
92			s->capture.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
93			s->output.type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
94			return 0;
95			}
96
97			return AVERROR(EINVAL);
98			}
99
100			static int v4l2_probe_driver(V4L2m2mContext *s)
101			{
102			void *log_ctx = s->avctx;
103			int ret;
104
105			s->fd = open(s->devname, O_RDWR \| O_NONBLOCK, 0);
106			if (s->fd < 0)
107			return AVERROR(errno);
108
109			ret = v4l2_prepare_contexts(s, 1);
110			if (ret < 0)
111			goto done;
112
113			ret = ff_v4l2_context_get_format(&s->output, 1);
114			if (ret) {
115			av_log(log_ctx, AV_LOG_DEBUG, "v4l2 output format not supported\n");
116			goto done;
117			}
118
119			ret = ff_v4l2_context_get_format(&s->capture, 1);
120			if (ret) {
121			av_log(log_ctx, AV_LOG_DEBUG, "v4l2 capture format not supported\n");
122			goto done;
123			}
124
125			done:
126			if (close(s->fd) < 0) {
127			ret = AVERROR(errno);
128			av_log(log_ctx, AV_LOG_ERROR, "failure closing %s (%s)\n", s->devname, av_err2str(AVERROR(errno)));
129			}
130
131			s->fd = -1;
132
133			return ret;
134			}
135
136			static int v4l2_configure_contexts(V4L2m2mContext *s)
137			{
138			void *log_ctx = s->avctx;
139			int ret;
140			struct v4l2_format ofmt, cfmt;
141
142			s->fd = open(s->devname, O_RDWR \| O_NONBLOCK, 0);
143			if (s->fd < 0)
144			return AVERROR(errno);
145
146			ret = v4l2_prepare_contexts(s, 0);
147			if (ret < 0)
148			goto error;
149
150			ofmt = s->output.format;
151			cfmt = s->capture.format;
152			av_log(log_ctx, AV_LOG_INFO, "requesting formats: output=%s capture=%s\n",
153			av_fourcc2str(V4L2_TYPE_IS_MULTIPLANAR(ofmt.type) ?
154			ofmt.fmt.pix_mp.pixelformat :
155			ofmt.fmt.pix.pixelformat),
156			av_fourcc2str(V4L2_TYPE_IS_MULTIPLANAR(cfmt.type) ?
157			cfmt.fmt.pix_mp.pixelformat :
158			cfmt.fmt.pix.pixelformat));
159
160			ret = ff_v4l2_context_set_format(&s->output);
161			if (ret) {
162			av_log(log_ctx, AV_LOG_ERROR, "can't set v4l2 output format\n");
163			goto error;
164			}
165
166			ret = ff_v4l2_context_set_format(&s->capture);
167			if (ret) {
168			av_log(log_ctx, AV_LOG_ERROR, "can't to set v4l2 capture format\n");
169			goto error;
170			}
171
172			ret = ff_v4l2_context_init(&s->output);
173			if (ret) {
174			av_log(log_ctx, AV_LOG_ERROR, "no v4l2 output context's buffers\n");
175			goto error;
176			}
177
178			/* decoder's buffers need to be updated at a later stage */
179			if (s->avctx && !av_codec_is_decoder(s->avctx->codec)) {
180			ret = ff_v4l2_context_init(&s->capture);
181			if (ret) {
182			av_log(log_ctx, AV_LOG_ERROR, "no v4l2 capture context's buffers\n");
183			goto error;
184			}
185			}
186
187			return 0;
188
189			error:
190			if (close(s->fd) < 0) {
191			ret = AVERROR(errno);
192			av_log(log_ctx, AV_LOG_ERROR, "error closing %s (%s)\n",
193			s->devname, av_err2str(AVERROR(errno)));
194			}
195			s->fd = -1;
196
197			return ret;
198			}
199
200			/******************************************************************************
201			*
202			* V4L2 M2M Interface
203			*
204			******************************************************************************/
205			int ff_v4l2_m2m_codec_reinit(V4L2m2mContext *s)
206			{
207			void *log_ctx = s->avctx;
208			int ret;
209
210			av_log(log_ctx, AV_LOG_DEBUG, "reinit context\n");
211
212			/* 1. streamoff */
213			ret = ff_v4l2_context_set_status(&s->capture, VIDIOC_STREAMOFF);
214			if (ret)
215			av_log(log_ctx, AV_LOG_ERROR, "capture VIDIOC_STREAMOFF\n");
216
217			/* 2. unmap the capture buffers (v4l2 and ffmpeg):
218			* we must wait for all references to be released before being allowed
219			* to queue new buffers.
220			*/
221			av_log(log_ctx, AV_LOG_DEBUG, "waiting for user to release AVBufferRefs\n");
222			if (atomic_load(&s->refcount))
223			while(sem_wait(&s->refsync) == -1 && errno == EINTR);
224
225			ff_v4l2_context_release(&s->capture);
226
227			/* 3. get the new capture format */
228			ret = ff_v4l2_context_get_format(&s->capture, 0);
229			if (ret) {
230			av_log(log_ctx, AV_LOG_ERROR, "query the new capture format\n");
231			return ret;
232			}
233
234			/* 4. set the capture format */
235			ret = ff_v4l2_context_set_format(&s->capture);
236			if (ret) {
237			av_log(log_ctx, AV_LOG_ERROR, "setting capture format\n");
238			return ret;
239			}
240
241			/* 5. complete reinit */
242			s->draining = 0;
243			s->reinit = 0;
244
245			return 0;
246			}
247
248			int ff_v4l2_m2m_codec_full_reinit(V4L2m2mContext *s)
249			{
250			void *log_ctx = s->avctx;
251			int ret;
252
253			av_log(log_ctx, AV_LOG_DEBUG, "%s full reinit\n", s->devname);
254
255			/* wait for pending buffer references */
256			if (atomic_load(&s->refcount))
257			while(sem_wait(&s->refsync) == -1 && errno == EINTR);
258
259			ret = ff_v4l2_context_set_status(&s->output, VIDIOC_STREAMOFF);
260			if (ret) {
261			av_log(log_ctx, AV_LOG_ERROR, "output VIDIOC_STREAMOFF\n");
262			goto error;
263			}
264
265			ret = ff_v4l2_context_set_status(&s->capture, VIDIOC_STREAMOFF);
266			if (ret) {
267			av_log(log_ctx, AV_LOG_ERROR, "capture VIDIOC_STREAMOFF\n");
268			goto error;
269			}
270
271			/* release and unmmap the buffers */
272			ff_v4l2_context_release(&s->output);
273			ff_v4l2_context_release(&s->capture);
274
275			/* start again now that we know the stream dimensions */
276			s->draining = 0;
277			s->reinit = 0;
278
279			ret = ff_v4l2_context_get_format(&s->output, 0);
280			if (ret) {
281			av_log(log_ctx, AV_LOG_DEBUG, "v4l2 output format not supported\n");
282			goto error;
283			}
284
285			ret = ff_v4l2_context_get_format(&s->capture, 0);
286			if (ret) {
287			av_log(log_ctx, AV_LOG_DEBUG, "v4l2 capture format not supported\n");
288			goto error;
289			}
290
291			ret = ff_v4l2_context_set_format(&s->output);
292			if (ret) {
293			av_log(log_ctx, AV_LOG_ERROR, "can't set v4l2 output format\n");
294			goto error;
295			}
296
297			ret = ff_v4l2_context_set_format(&s->capture);
298			if (ret) {
299			av_log(log_ctx, AV_LOG_ERROR, "can't to set v4l2 capture format\n");
300			goto error;
301			}
302
303			ret = ff_v4l2_context_init(&s->output);
304			if (ret) {
305			av_log(log_ctx, AV_LOG_ERROR, "no v4l2 output context's buffers\n");
306			goto error;
307			}
308
309			/* decoder's buffers need to be updated at a later stage */
310			if (s->avctx && !av_codec_is_decoder(s->avctx->codec)) {
311			ret = ff_v4l2_context_init(&s->capture);
312			if (ret) {
313			av_log(log_ctx, AV_LOG_ERROR, "no v4l2 capture context's buffers\n");
314			goto error;
315			}
316			}
317
318			return 0;
319
320			error:
321			return ret;
322			}
323
324			static void v4l2_m2m_destroy_context(void opaque, uint8_t context)
325			{
326			V4L2m2mContext s = (V4L2m2mContext)context;
327
328			ff_v4l2_context_release(&s->capture);
329			sem_destroy(&s->refsync);
330
331			close(s->fd);
332			av_frame_unref(s->frame);
333			av_frame_free(&s->frame);
334			av_packet_unref(&s->buf_pkt);
335
336			av_free(s);
337			}
338
339			int ff_v4l2_m2m_codec_end(V4L2m2mPriv *priv)
340			{
341			V4L2m2mContext *s = priv->context;
342			int ret;
343
344			if (!s)
345			return 0;
346
347			if (s->fd >= 0) {
348			ret = ff_v4l2_context_set_status(&s->output, VIDIOC_STREAMOFF);
349			if (ret)
350			av_log(s->avctx, AV_LOG_ERROR, "VIDIOC_STREAMOFF %s\n", s->output.name);
351
352			ret = ff_v4l2_context_set_status(&s->capture, VIDIOC_STREAMOFF);
353			if (ret)
354			av_log(s->avctx, AV_LOG_ERROR, "VIDIOC_STREAMOFF %s\n", s->capture.name);
355			}
356
357			ff_v4l2_context_release(&s->output);
358
359			s->self_ref = NULL;
360			av_buffer_unref(&priv->context_ref);
361
362			return 0;
363			}
364
365			int ff_v4l2_m2m_codec_init(V4L2m2mPriv *priv)
366			{
367			int ret = AVERROR(EINVAL);
368			struct dirent *entry;
369			DIR *dirp;
370
371			V4L2m2mContext *s = priv->context;
372
373			dirp = opendir("/dev");
374			if (!dirp)
375			return AVERROR(errno);
376
377			for (entry = readdir(dirp); entry; entry = readdir(dirp)) {
378
379			if (strncmp(entry->d_name, "video", 5))
380			continue;
381
382			snprintf(s->devname, sizeof(s->devname), "/dev/%s", entry->d_name);
383			av_log(s->avctx, AV_LOG_DEBUG, "probing device %s\n", s->devname);
384			ret = v4l2_probe_driver(s);
385			if (!ret)
386			break;
387			}
388
389			closedir(dirp);
390
391			if (ret) {
392			av_log(s->avctx, AV_LOG_ERROR, "Could not find a valid device\n");
393			memset(s->devname, 0, sizeof(s->devname));
394
395			return ret;
396			}
397
398			av_log(s->avctx, AV_LOG_INFO, "Using device %s\n", s->devname);
399
400			return v4l2_configure_contexts(s);
401			}
402
403			int ff_v4l2_m2m_create_context(V4L2m2mPriv priv, V4L2m2mContext *s)
404			{
405			*s = av_mallocz(sizeof(V4L2m2mContext));
406			if (!*s)
407			return AVERROR(ENOMEM);
408
409			priv->context_ref = av_buffer_create((uint8_t ) s, sizeof(V4L2m2mContext),
410			&v4l2_m2m_destroy_context, NULL, 0);
411			if (!priv->context_ref) {
412			av_freep(s);
413			return AVERROR(ENOMEM);
414			}
415
416			/* assign the context */
417			priv->context = *s;
418			(*s)->priv = priv;
419
420			/* populate it */
421			priv->context->capture.num_buffers = priv->num_capture_buffers;
422			priv->context->output.num_buffers = priv->num_output_buffers;
423			priv->context->self_ref = priv->context_ref;
424			priv->context->fd = -1;
425
426			priv->context->frame = av_frame_alloc();
427			if (!priv->context->frame) {
428			av_buffer_unref(&priv->context_ref);
429			s = NULL; / freed when unreferencing context_ref */
430			return AVERROR(ENOMEM);
431			}
432
433			return 0;
434			}