video-play-sync.c

Video input stream using pw_stream and sync timeline.

Video input stream using pw_stream and sync timeline.

/* PipeWire */
/* SPDX-FileCopyrightText: Copyright © 2025 Wim Taymans */
/* SPDX-License-Identifier: MIT */
 
/*
 [title]
 Video input stream using \ref pw_stream "pw_stream" and sync timeline.
 [title]
 */
 
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <getopt.h>
 
#include <spa/utils/result.h>
#include <spa/param/video/format-utils.h>
#include <spa/param/tag-utils.h>
#include <spa/param/props.h>
#include <spa/param/latency-utils.h>
#include <spa/debug/format.h>
#include <spa/debug/pod.h>
 
#include <pipewire/pipewire.h>
 
#define WIDTH   1920
#define HEIGHT  1080
#define RATE    30
 
#define MAX_BUFFERS     64
 
#include "sdl.h"
 
struct pixel {
        float r, g, b, a;
};
 
struct data {
        const char *path;
 
        SDL_Renderer *renderer;
        SDL_Window *window;
        SDL_Texture *texture;
 
        struct pw_main_loop *loop;
 
        struct pw_stream *stream;
        struct spa_hook stream_listener;
 
        struct spa_io_position *position;
 
        struct spa_video_info format;
        int32_t stride;
        struct spa_rectangle size;
 
        int counter;
        SDL_Rect rect;
        bool is_yuv;
 
        bool with_synctimeline;
        bool with_synctimeline_release;
};
 
static void handle_events(struct data *data)
{
        SDL_Event event;
        while (SDL_PollEvent(&event)) {
                switch (event.type) {
                case SDL_QUIT:
                        pw_main_loop_quit(data->loop);
                        break;
                }
        }
}
 
/* our data processing function is in general:
 *
 *  struct pw_buffer *b;
 *  b = pw_stream_dequeue_buffer(stream);
 *
 *  .. do stuff with buffer ...
 *
 *  pw_stream_queue_buffer(stream, b);
 */
static void
on_process(void *_data)
{
        struct data *data = _data;
        struct pw_stream *stream = data->stream;
        struct pw_buffer *b;
        struct spa_buffer *buf;
        void *sdata, *ddata;
        int sstride, dstride, ostride;
        struct spa_meta_header *h;
        struct spa_meta_sync_timeline *stl = NULL;
        uint32_t i, j;
        uint8_t *src, *dst;
        uint64_t cmd;
 
        b = NULL;
        while (true) {
                struct pw_buffer *t;
                if ((t = pw_stream_dequeue_buffer(stream)) == NULL)
                        break;
                if (b)
                        pw_stream_queue_buffer(stream, b);
                b = t;
        }
        if (b == NULL) {
                pw_log_warn("out of buffers: %m");
                return;
        }
 
        buf = b->buffer;
 
        pw_log_trace("new buffer %p", buf);
 
        handle_events(data);
 
        if ((sdata = buf->datas[0].data) == NULL)
                goto done;
 
        if ((h = spa_buffer_find_meta_data(buf, SPA_META_Header, sizeof(*h)))) {
                uint64_t now = pw_stream_get_nsec(stream);
                pw_log_debug("now:%"PRIu64" pts:%"PRIu64" diff:%"PRIi64,
                                now, h->pts, now - h->pts);
        }
        if ((stl = spa_buffer_find_meta_data(buf, SPA_META_SyncTimeline, sizeof(*stl))) &&
            stl->acquire_point) {
                /* wait before we can use the buffer */
                if (read(buf->datas[1].fd, &cmd, sizeof(cmd)) < 0)
                        pw_log_warn("acquire_point wait error %m");
                pw_log_debug("acquire_point:%"PRIu64, stl->acquire_point);
        }
 
        /* copy video image in texture */
        if (data->is_yuv) {
                void *datas[4];
                sstride = data->stride;
                if (buf->n_datas == 1) {
                        SDL_UpdateTexture(data->texture, NULL,
                                        sdata, sstride);
                } else {
                        datas[0] = sdata;
                        datas[1] = buf->datas[1].data;
                        datas[2] = buf->datas[2].data;
                        SDL_UpdateYUVTexture(data->texture, NULL,
                                        datas[0], sstride,
                                        datas[1], sstride / 2,
                                        datas[2], sstride / 2);
                }
        }
        else {
                if (SDL_LockTexture(data->texture, NULL, &ddata, &dstride) < 0) {
                        fprintf(stderr, "Couldn't lock texture: %s\n", SDL_GetError());
                }
 
                sstride = buf->datas[0].chunk->stride;
                if (sstride == 0)
                        sstride = buf->datas[0].chunk->size / data->size.height;
                ostride = SPA_MIN(sstride, dstride);
 
                src = sdata;
                dst = ddata;
 
                if (data->format.media_subtype == SPA_MEDIA_SUBTYPE_dsp) {
                        for (i = 0; i < data->size.height; i++) {
                                struct pixel *p = (struct pixel *) src;
                                for (j = 0; j < data->size.width; j++) {
                                        dst[j * 4 + 0] = SPA_CLAMP((uint8_t)(p[j].r * 255.0f), 0u, 255u);
                                        dst[j * 4 + 1] = SPA_CLAMP((uint8_t)(p[j].g * 255.0f), 0u, 255u);
                                        dst[j * 4 + 2] = SPA_CLAMP((uint8_t)(p[j].b * 255.0f), 0u, 255u);
                                        dst[j * 4 + 3] = SPA_CLAMP((uint8_t)(p[j].a * 255.0f), 0u, 255u);
                                }
                                src += sstride;
                                dst += dstride;
                        }
                } else {
                        for (i = 0; i < data->size.height; i++) {
                                memcpy(dst, src, ostride);
                                src += sstride;
                                dst += dstride;
                        }
                }
                SDL_UnlockTexture(data->texture);
        }
 
        SDL_RenderClear(data->renderer);
        /* now render the video */
        SDL_RenderCopy(data->renderer, data->texture, &data->rect, NULL);
        SDL_RenderPresent(data->renderer);
 
      done:
        pw_stream_queue_buffer(stream, b);
 
        if (stl != NULL && stl->release_point) {
                /* we promise to signal the release point */
                if (data->with_synctimeline_release)
                        SPA_FLAG_CLEAR(stl->flags, SPA_META_SYNC_TIMELINE_UNSCHEDULED_RELEASE);
                cmd = 1;
                /* signal buffer release point */
                write(buf->datas[2].fd, &cmd, sizeof(cmd));
                pw_log_debug("release:%"PRIu64, stl->release_point);
        }
}
 
static void on_stream_state_changed(void *_data, enum pw_stream_state old,
                                    enum pw_stream_state state, const char *error)
{
        struct data *data = _data;
        fprintf(stderr, "stream state: \"%s\"\n", pw_stream_state_as_string(state));
        switch (state) {
        case PW_STREAM_STATE_UNCONNECTED:
                pw_main_loop_quit(data->loop);
                break;
        case PW_STREAM_STATE_PAUSED:
                /* because we started inactive, activate ourselves now */
                pw_stream_set_active(data->stream, true);
                break;
        default:
                break;
        }
}
 
static void
on_stream_io_changed(void *_data, uint32_t id, void *area, uint32_t size)
{
        struct data *data = _data;
 
        switch (id) {
        case SPA_IO_Position:
                data->position = area;
                break;
        }
}
 
/* Be notified when the stream param changes. We're only looking at the
 * format changes.
 *
 * We are now supposed to call pw_stream_finish_format() with success or
 * failure, depending on if we can support the format. Because we gave
 * a list of supported formats, this should be ok.
 *
 * As part of pw_stream_finish_format() we can provide parameters that
 * will control the buffer memory allocation. This includes the metadata
 * that we would like on our buffer, the size, alignment, etc.
 */
static void
on_stream_param_changed(void *_data, uint32_t id, const struct spa_pod *param)
{
        struct data *data = _data;
        struct pw_stream *stream = data->stream;
        uint8_t params_buffer[1024];
        struct spa_pod_builder b = SPA_POD_BUILDER_INIT(params_buffer, sizeof(params_buffer));
        struct spa_pod_frame f;
        const struct spa_pod *params[5];
        uint32_t n_params = 0;
        Uint32 sdl_format;
        void *d;
        int32_t mult, size, blocks;
 
        if (param != NULL && id == SPA_PARAM_Tag) {
                spa_debug_pod(0, NULL, param);
                return;
        }
        if (param != NULL && id == SPA_PARAM_Latency) {
                struct spa_latency_info info;
                if (spa_latency_parse(param, &info) >= 0)
                        fprintf(stderr, "got latency: %"PRIu64"\n", (info.min_ns + info.max_ns) / 2);
                return;
        }
        /* NULL means to clear the format */
        if (param == NULL || id != SPA_PARAM_Format)
                return;
 
        fprintf(stderr, "got format:\n");
        spa_debug_format(2, NULL, param);
 
        if (spa_format_parse(param, &data->format.media_type, &data->format.media_subtype) < 0)
                return;
 
        if (data->format.media_type != SPA_MEDIA_TYPE_video)
                return;
 
        switch (data->format.media_subtype) {
        case SPA_MEDIA_SUBTYPE_raw:
                /* call a helper function to parse the format for us. */
                spa_format_video_raw_parse(param, &data->format.info.raw);
                sdl_format = id_to_sdl_format(data->format.info.raw.format);
                data->size = SPA_RECTANGLE(data->format.info.raw.size.width,
                                data->format.info.raw.size.height);
                mult = 1;
                break;
        case SPA_MEDIA_SUBTYPE_dsp:
                spa_format_video_dsp_parse(param, &data->format.info.dsp);
                if (data->format.info.dsp.format != SPA_VIDEO_FORMAT_DSP_F32)
                        return;
                sdl_format = SDL_PIXELFORMAT_RGBA32;
                data->size = SPA_RECTANGLE(data->position->video.size.width,
                                data->position->video.size.height);
                mult = 4;
                break;
        default:
                sdl_format = SDL_PIXELFORMAT_UNKNOWN;
                break;
        }
 
        if (sdl_format == SDL_PIXELFORMAT_UNKNOWN) {
                pw_stream_set_error(stream, -EINVAL, "unknown pixel format");
                return;
        }
        if (data->size.width == 0 || data->size.height == 0) {
                pw_stream_set_error(stream, -EINVAL, "invalid size");
                return;
        }
 
        data->texture = SDL_CreateTexture(data->renderer,
                                          sdl_format,
                                          SDL_TEXTUREACCESS_STREAMING,
                                          data->size.width,
                                          data->size.height);
        switch(sdl_format) {
        case SDL_PIXELFORMAT_YV12:
        case SDL_PIXELFORMAT_IYUV:
                data->stride = data->size.width;
                size = (data->stride * data->size.height) * 3 / 2;
                data->is_yuv = true;
                blocks = 3;
                break;
        case SDL_PIXELFORMAT_YUY2:
                data->is_yuv = true;
                data->stride = data->size.width * 2;
                size = (data->stride * data->size.height);
                blocks = 1;
                break;
        default:
                if (SDL_LockTexture(data->texture, NULL, &d, &data->stride) < 0) {
                        fprintf(stderr, "Couldn't lock texture: %s\n", SDL_GetError());
                        data->stride = data->size.width * 2;
                } else
                        SDL_UnlockTexture(data->texture);
                size = data->stride * data->size.height;
                blocks = 1;
                break;
        }
 
        data->rect.x = 0;
        data->rect.y = 0;
        data->rect.w = data->size.width;
        data->rect.h = data->size.height;
 
        if (data->with_synctimeline) {
                /* first add Buffer with 3 blocks (1 data, 2 sync fds). */
                spa_pod_builder_push_object(&b, &f, SPA_TYPE_OBJECT_ParamBuffers, SPA_PARAM_Buffers);
                spa_pod_builder_add(&b,
                        SPA_PARAM_BUFFERS_buffers, SPA_POD_CHOICE_RANGE_Int(8, 2, MAX_BUFFERS),
                        SPA_PARAM_BUFFERS_blocks,  SPA_POD_Int(3),
                        SPA_PARAM_BUFFERS_size,    SPA_POD_Int(size * mult),
                        SPA_PARAM_BUFFERS_stride,  SPA_POD_Int(data->stride * mult),
                        SPA_PARAM_BUFFERS_dataType, SPA_POD_CHOICE_FLAGS_Int((1<<SPA_DATA_MemFd)),
                        0);
                /* this depends on the negotiation of the SyncTimeline metadata */
                spa_pod_builder_prop(&b, SPA_PARAM_BUFFERS_metaType, SPA_POD_PROP_FLAG_MANDATORY);
                spa_pod_builder_int(&b, 1<<SPA_META_SyncTimeline);
                params[n_params++] = spa_pod_builder_pop(&b, &f);
 
                /* explicit sync information */
                spa_pod_builder_push_object(&b, &f, SPA_TYPE_OBJECT_ParamMeta, SPA_PARAM_Meta);
                spa_pod_builder_add(&b,
                        SPA_PARAM_META_type, SPA_POD_Id(SPA_META_SyncTimeline),
                        SPA_PARAM_META_size, SPA_POD_Int(sizeof(struct spa_meta_sync_timeline)),
                        0);
                if (data->with_synctimeline_release) {
                        /* drop features flags if not provided by both sides */
                        spa_pod_builder_prop(&b, SPA_PARAM_META_features, SPA_POD_PROP_FLAG_DROP);
                        spa_pod_builder_int(&b, SPA_META_FEATURE_SYNC_TIMELINE_RELEASE);
                }
                params[n_params++] = spa_pod_builder_pop(&b, &f);
        }
 
        /* fallback for when the synctimeline is not negotiated */
        params[n_params++] = spa_pod_builder_add_object(&b,
                SPA_TYPE_OBJECT_ParamBuffers, SPA_PARAM_Buffers,
                SPA_PARAM_BUFFERS_buffers, SPA_POD_CHOICE_RANGE_Int(8, 2, MAX_BUFFERS),
                SPA_PARAM_BUFFERS_blocks,  SPA_POD_Int(blocks),
                SPA_PARAM_BUFFERS_size,    SPA_POD_Int(size * mult),
                SPA_PARAM_BUFFERS_stride,  SPA_POD_Int(data->stride * mult),
                SPA_PARAM_BUFFERS_dataType, SPA_POD_CHOICE_FLAGS_Int((1<<SPA_DATA_MemFd)));
 
        /* a header metadata with timing information */
        params[n_params++] = spa_pod_builder_add_object(&b,
                SPA_TYPE_OBJECT_ParamMeta, SPA_PARAM_Meta,
                SPA_PARAM_META_type, SPA_POD_Id(SPA_META_Header),
                SPA_PARAM_META_size, SPA_POD_Int(sizeof(struct spa_meta_header)));
 
        /* we are done */
        pw_stream_update_params(stream, params, n_params);
}
 
static void on_stream_add_buffer(void *_data, struct pw_buffer *buffer)
{
}
 
/* these are the stream events we listen for */
static const struct pw_stream_events stream_events = {
        PW_VERSION_STREAM_EVENTS,
        .state_changed = on_stream_state_changed,
        .io_changed = on_stream_io_changed,
        .param_changed = on_stream_param_changed,
        .process = on_process,
        .add_buffer = on_stream_add_buffer,
};
 
static int build_format(struct data *data, struct spa_pod_builder *b, const struct spa_pod **params)
{
        uint32_t n_params = 0;
        SDL_RendererInfo info;
 
        SDL_GetRendererInfo(data->renderer, &info);
        params[n_params++] = sdl_build_formats(&info, b);
 
        fprintf(stderr, "supported SDL formats:\n");
        spa_debug_format(2, NULL, params[0]);
 
        params[n_params++] = spa_pod_builder_add_object(b,
                        SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
                        SPA_FORMAT_mediaType,           SPA_POD_Id(SPA_MEDIA_TYPE_video),
                        SPA_FORMAT_mediaSubtype,        SPA_POD_Id(SPA_MEDIA_SUBTYPE_dsp),
                        SPA_FORMAT_VIDEO_format,        SPA_POD_Id(SPA_VIDEO_FORMAT_DSP_F32));
 
        fprintf(stderr, "supported DSP formats:\n");
        spa_debug_format(2, NULL, params[1]);
 
        return n_params;
}
 
static void do_quit(void *userdata, int signal_number)
{
        struct data *data = userdata;
        pw_main_loop_quit(data->loop);
}
 
static void show_help(struct data *data, const char *name, bool is_error)
{
        FILE *fp;
 
        fp = is_error ? stderr : stdout;
 
        fprintf(fp,
                "%s [options]\n"
                "  -h, --help                            Show this help\n"
                "      --version                         Show version\n"
                "  -r, --remote                          Remote daemon name\n"
                "  -S, --sync                            Enable SyncTimeline\n"
                "  -R, --release                         Enable RELEASE feature\n"
                "\n", name);
}
 
int main(int argc, char *argv[])
{
        struct data data = { 0, };
        const struct spa_pod *params[3];
        uint8_t buffer[1024];
        struct spa_pod_builder b = SPA_POD_BUILDER_INIT(buffer, sizeof(buffer));
        struct pw_properties *props;
        int res, n_params;
        static const struct option long_options[] = {
                { "help",       no_argument,            NULL, 'h' },
                { "version",    no_argument,            NULL, 'V' },
                { "remote",     required_argument,      NULL, 'r' },
                { "sync",       no_argument,            NULL, 'S' },
                { "release",    no_argument,            NULL, 'R' },
                { NULL, 0, NULL, 0}
        };
        char *opt_remote = NULL;
        int c;
 
        pw_init(&argc, &argv);
 
        while ((c = getopt_long(argc, argv, "hVr:SR", long_options, NULL)) != -1) {
                switch (c) {
                case 'h':
                        show_help(&data, argv[0], false);
                        return 0;
                case 'V':
                        printf("%s\n"
                                "Compiled with libpipewire %s\n"
                                "Linked with libpipewire %s\n",
                                argv[0],
                                pw_get_headers_version(),
                                pw_get_library_version());
                        return 0;
                case 'r':
                        opt_remote = optarg;
                        break;
                case 'S':
                        data.with_synctimeline = true;
                        break;
                case 'R':
                        data.with_synctimeline_release = true;
                        break;
                default:
                        show_help(&data, argv[0], true);
                        return -1;
                }
        }
 
        /* create a main loop */
        data.loop = pw_main_loop_new(NULL);
 
        pw_loop_add_signal(pw_main_loop_get_loop(data.loop), SIGINT, do_quit, &data);
        pw_loop_add_signal(pw_main_loop_get_loop(data.loop), SIGTERM, do_quit, &data);
 
        /* create a simple stream, the simple stream manages to core and remote
         * objects for you if you don't need to deal with them
         *
         * If you plan to autoconnect your stream, you need to provide at least
         * media, category and role properties
         *
         * Pass your events and a user_data pointer as the last arguments. This
         * will inform you about the stream state. The most important event
         * you need to listen to is the process event where you need to consume
         * the data provided to you.
         */
        props = pw_properties_new(PW_KEY_MEDIA_TYPE, "Video",
                        PW_KEY_MEDIA_CATEGORY, "Capture",
                        PW_KEY_MEDIA_ROLE, "Camera",
                        PW_KEY_REMOTE_NAME, opt_remote,
                        NULL),
 
        data.path = optind < argc ? argv[optind++] : "video-src-sync";
        if (data.path)
                pw_properties_set(props, PW_KEY_TARGET_OBJECT, data.path);
 
        data.stream = pw_stream_new_simple(
                        pw_main_loop_get_loop(data.loop),
                        "video-play",
                        props,
                        &stream_events,
                        &data);
 
        if (SDL_Init(SDL_INIT_VIDEO) < 0) {
                fprintf(stderr, "can't initialize SDL: %s\n", SDL_GetError());
                return -1;
        }
 
        if (SDL_CreateWindowAndRenderer
            (WIDTH, HEIGHT, SDL_WINDOW_RESIZABLE, &data.window, &data.renderer)) {
                fprintf(stderr, "can't create window: %s\n", SDL_GetError());
                return -1;
        }
 
        /* build the extra parameters to connect with. To connect, we can provide
         * a list of supported formats.  We use a builder that writes the param
         * object to the stack. */
        n_params = build_format(&data, &b, params);
 
        /* now connect the stream, we need a direction (input/output),
         * an optional target node to connect to, some flags and parameters
         */
        if ((res = pw_stream_connect(data.stream,
                          PW_DIRECTION_INPUT,
                          PW_ID_ANY,
                          PW_STREAM_FLAG_AUTOCONNECT |  /* try to automatically connect this stream */
                          PW_STREAM_FLAG_INACTIVE |     /* we will activate ourselves */
                          PW_STREAM_FLAG_MAP_BUFFERS,   /* mmap the buffer data for us */
                          params, n_params))            /* extra parameters, see above */ < 0) {
                fprintf(stderr, "can't connect: %s\n", spa_strerror(res));
                return -1;
        }
 
        /* do things until we quit the mainloop */
        pw_main_loop_run(data.loop);
 
        pw_stream_destroy(data.stream);
        pw_main_loop_destroy(data.loop);
 
        SDL_DestroyTexture(data.texture);
        SDL_DestroyRenderer(data.renderer);
        SDL_DestroyWindow(data.window);
        pw_deinit();
 
        return 0;
}