video_capture.c

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/*
 * Copyright (c) 2005-2024 CESNET
 * Copyright (c) 2001-2004 University of Southern California
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, is permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 * 
 *      This product includes software developed by the University of Southern
 *      California Information Sciences Institute. This product also includes
 *      software developed by CESNET z.s.p.o.
 * 
 * 4. Neither the name of the University, Institute, CESNET nor the names of
 *    its contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
 
#include <assert.h>                // for assert
#include <stdint.h>                // for uint32_t
#include <stdio.h>                 // for printf
#include <stdlib.h>                // for NULL, free, malloc, size_t
 
#include "capture_filter.h"
#include "debug.h"
#include "lib_common.h"
#include "module.h"
#include "utils/macros.h"
#include "video_capture.h"
#include "video_capture_params.h"
 
#define VIDCAP_MAGIC    0x76ae98f0
 
struct vidcap {
        struct module mod;
        void    *state; 
        const struct video_capture_info *funcs;
        uint32_t magic; 
 
        struct capture_filter *capture_filter; 
};
 
/* API for probing capture devices ****************************************************************/
void list_video_capture_devices(bool full)
{
        printf("Available capture devices:\n");
        list_modules(LIBRARY_CLASS_VIDEO_CAPTURE, VIDEO_CAPTURE_ABI_VERSION, full);
}
 
int initialize_video_capture(struct module *parent,
                struct vidcap_params *param,
                struct vidcap **state)
{
        struct vidcap_params *tlast = param;
        struct vidcap_params *tprev = param;
        while ((vidcap_params_get_next(tlast))) {
                tprev = tlast;
                tlast = vidcap_params_get_next(tlast);
        }
        if (vidcap_params_get_driver(tlast) == NULL
                        && vidcap_params_get_capture_filter(tlast) != NULL) {
                if (tprev != param) { // more than one -t
                        log_msg(LOG_LEVEL_ERROR, "Capture filter (--capture-filter) needs to be "
                                "specified before capture (-t)\n");
                        return -1;
                }
                if (vidcap_params_get_capture_filter(tprev) != NULL) { // one -t but -F specified both before and after it
                        log_msg(LOG_LEVEL_ERROR, "Multiple capture filter specification.\n");
                        return -1;
                }
                vidcap_params_set_capture_filter(tprev, vidcap_params_get_capture_filter(tlast));
        }
        // similarly for audio connection
        if (vidcap_params_get_driver(tlast) == NULL
                        && vidcap_params_get_flags(tlast) != 0) {
                if (tprev != param) { // more than one -t
                        log_msg(LOG_LEVEL_ERROR, "Audio connection (-s) needs to be "
                                "specified before capture (-t)\n");
                        return -1;
                }
                if (vidcap_params_get_flags(tprev) != 0) { // one -t but -s specified both before and after it
                        log_msg(LOG_LEVEL_ERROR, "Multiple audio connection specification.\n");
                        return -1;
                }
                vidcap_params_set_flags(tprev, vidcap_params_get_flags(tlast));
        }
 
        const struct video_capture_info *vci = (const struct video_capture_info *)
                load_library(vidcap_params_get_driver(param), LIBRARY_CLASS_VIDEO_CAPTURE, VIDEO_CAPTURE_ABI_VERSION);
 
        if (vci == NULL) {
                log_msg(LOG_LEVEL_ERROR, "WARNING: Selected '%s' capture card "
                        "was not found.\n", vidcap_params_get_driver(param));
                return -1;
        }
 
        struct vidcap *d =
                (struct vidcap *)malloc(sizeof(struct vidcap));
        d->magic = VIDCAP_MAGIC;
        d->funcs = vci;
 
        module_init_default(&d->mod);
        d->mod.cls = MODULE_CLASS_CAPTURE;
        module_register(&d->mod, parent);
 
        vidcap_params_set_parent(param, &d->mod);
        int ret = vci->init(param, &d->state);
 
        switch (ret) {
        case VIDCAP_INIT_OK:
                break;
        case VIDCAP_INIT_NOERR:
                break;
        case VIDCAP_INIT_FAIL:
                log_msg(LOG_LEVEL_ERROR,
                                "Unable to start video capture device %s\n",
                                vidcap_params_get_driver(param));
                break;
        case VIDCAP_INIT_AUDIO_NOT_SUPPORTED:
                log_msg(LOG_LEVEL_ERROR,
                                "Video capture driver does not support selected embedded/analog/AESEBU audio.\n");
                break;
        }
        if (ret != 0) {
                module_done(&d->mod);
                free(d);
                return ret;
        }
 
        ret = capture_filter_init(&d->mod, vidcap_params_get_capture_filter(param),
                &d->capture_filter);
        if (ret < 0) {
                log_msg(LOG_LEVEL_ERROR, "Unable to initialize capture filter: %s.\n",
                        vidcap_params_get_capture_filter(param));
        }
 
        if (ret != 0) {
                module_done(&d->mod);
                free(d);
                return ret;
        }
 
        *state = d;
        return 0;
}
 
void vidcap_done(struct vidcap *state)
{
        assert(state->magic == VIDCAP_MAGIC);
        state->funcs->done(state->state);
        capture_filter_destroy(state->capture_filter);
        module_done(&state->mod);
        free(state);
}
 
struct video_frame *vidcap_grab(struct vidcap *state, struct audio_frame **audio)
{
        assert(state->magic == VIDCAP_MAGIC);
        struct video_frame *frame;
        frame = state->funcs->grab(state->state, audio);
        if (frame != NULL)
                frame = capture_filter(state->capture_filter, frame);
        return frame;
}
 
const char *vidcap_get_fps_print_prefix(struct vidcap *state)
{
        assert(state->magic == VIDCAP_MAGIC);
        if (state->funcs->generic_fps_indicator_prefix == NULL) {
                return NULL;
        }
        _Thread_local static char buf[SHORT_STR];
 
        unsigned len = snprintf(buf, sizeof buf, "%s",
                                state->funcs->generic_fps_indicator_prefix);
        if (len > sizeof buf - 1) { // truncated
                len = sizeof buf - 1;
        }
        if (len > 0 && buf[len - 1] == ' ') { // trim trailing ' '
                buf[len - 1] = '\0';
        }
        return buf;
}