export-sink.c

Exporting and implementing a video sink SPA node, using Core API.

/* PipeWire */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */
 
/*
 [title]
 Exporting and implementing a video sink SPA node, using \ref api_pw_core.
 [title]
 */
 
#include <errno.h>
#include <stdio.h>
#include <sys/mman.h>
 
#include <spa/utils/result.h>
#include <spa/param/video/format-utils.h>
#include <spa/param/props.h>
#include <spa/node/utils.h>
#include <spa/node/io.h>
#include <spa/pod/filter.h>
#include <spa/debug/format.h>
#include <spa/debug/pod.h>
 
#include <pipewire/pipewire.h>
 
#define WIDTH   640
#define HEIGHT  480
#define BPP    3
 
#include "sdl.h"
 
#define M_PI_M2 ( M_PI + M_PI )
 
#define MAX_BUFFERS     64
 
#define DEFAULT_PARAM 0.1
 
struct props {
        double param;
};
 
static void reset_props(struct props *props)
{
        props->param = DEFAULT_PARAM;
}
 
struct data {
        struct props props;
 
        const char *path;
 
        SDL_Renderer *renderer;
        SDL_Window *window;
        SDL_Texture *texture;
 
        struct pw_main_loop *loop;
 
        struct pw_context *context;
 
        struct pw_core *core;
        struct spa_hook core_listener;
 
        struct spa_node impl_node;
        struct spa_hook_list hooks;
        struct spa_io_buffers *io;
        struct spa_io_sequence *io_notify;
        uint32_t io_notify_size;
        double param_accum;
 
        uint8_t buffer[1024];
 
        struct spa_video_info_raw format;
        int32_t stride;
 
        struct spa_port_info info;
        struct spa_param_info params[5];
 
        struct spa_region region;
 
        struct spa_buffer *buffers[MAX_BUFFERS];
        uint32_t n_buffers;
};
 
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;
                }
        }
}
 
static void update_param(struct data *data)
{
        struct spa_pod_builder b = { 0, };
        struct spa_pod_frame f[2];
 
        if (data->io_notify == NULL)
                return;
 
        spa_pod_builder_init(&b, data->io_notify, data->io_notify_size);
        spa_pod_builder_push_sequence(&b, &f[0], 0);
        spa_pod_builder_control(&b, 0, SPA_CONTROL_Properties);
        spa_pod_builder_push_object(&b, &f[1], SPA_TYPE_OBJECT_Props, 0);
        spa_pod_builder_prop(&b, SPA_PROP_contrast, 0);
        spa_pod_builder_float(&b, (sin(data->param_accum) * 127.0) + 127.0);
        spa_pod_builder_pop(&b, &f[1]);
        spa_pod_builder_pop(&b, &f[0]);
 
        data->param_accum += M_PI_M2 / 30.0;
        if (data->param_accum >= M_PI_M2)
                data->param_accum -= M_PI_M2;
}
 
static int impl_send_command(void *object, const struct spa_command *command)
{
        return 0;
}
 
static int impl_add_listener(void *object,
                struct spa_hook *listener,
                const struct spa_node_events *events,
                void *data)
{
        struct data *d = object;
        struct spa_hook_list save;
        uint64_t old;
 
        spa_hook_list_isolate(&d->hooks, &save, listener, events, data);
 
        old = d->info.change_mask;
        d->info.change_mask = SPA_PORT_CHANGE_MASK_FLAGS |
                                SPA_PORT_CHANGE_MASK_PARAMS;
        spa_node_emit_port_info(&d->hooks, SPA_DIRECTION_INPUT, 0, &d->info);
        d->info.change_mask = old;
 
        spa_hook_list_join(&d->hooks, &save);
 
        return 0;
}
 
static int impl_set_callbacks(void *object,
                              const struct spa_node_callbacks *callbacks, void *data)
{
        return 0;
}
 
static int impl_set_io(void *object,
                            uint32_t id, void *data, size_t size)
{
        return 0;
}
 
static int impl_port_set_io(void *object,
                            enum spa_direction direction, uint32_t port_id,
                            uint32_t id, void *data, size_t size)
{
        struct data *d = object;
 
        switch (id) {
        case SPA_IO_Buffers:
                d->io = data;
                break;
        case SPA_IO_Notify:
                d->io_notify = data;
                d->io_notify_size = size;
                break;
        default:
                return -ENOENT;
        }
        return 0;
}
 
static int impl_port_enum_params(void *object, int seq,
                                 enum spa_direction direction, uint32_t port_id,
                                 uint32_t id, uint32_t start, uint32_t num,
                                 const struct spa_pod *filter)
{
        struct data *d = object;
        struct spa_pod *param;
        struct spa_pod_builder b = { 0 };
        uint8_t buffer[1024];
        struct spa_result_node_params result;
        uint32_t count = 0;
 
        result.id = id;
        result.next = start;
      next:
        result.index = result.next++;
 
        spa_pod_builder_init(&b, buffer, sizeof(buffer));
 
        switch (id) {
        case SPA_PARAM_EnumFormat:
        {
                SDL_RendererInfo info;
 
                if (result.index != 0)
                        return 0;
 
                SDL_GetRendererInfo(d->renderer, &info);
                param = sdl_build_formats(&info, &b);
                break;
        }
        case SPA_PARAM_Format:
                if (result.index != 0 || d->format.format == 0)
                        return 0;
                param = spa_format_video_raw_build(&b, id, &d->format);
                break;
 
        case SPA_PARAM_Buffers:
                if (result.index != 0)
                        return 0;
 
                param = spa_pod_builder_add_object(&b,
                        SPA_TYPE_OBJECT_ParamBuffers, id,
                        SPA_PARAM_BUFFERS_buffers, SPA_POD_CHOICE_RANGE_Int(2, 2, MAX_BUFFERS),
                        SPA_PARAM_BUFFERS_blocks,  SPA_POD_Int(1),
                        SPA_PARAM_BUFFERS_size,    SPA_POD_Int(d->stride * d->format.size.height),
                        SPA_PARAM_BUFFERS_stride,  SPA_POD_Int(d->stride));
                break;
 
        case SPA_PARAM_Meta:
                switch (result.index) {
                case 0:
                        param = spa_pod_builder_add_object(&b,
                                SPA_TYPE_OBJECT_ParamMeta, id,
                                SPA_PARAM_META_type, SPA_POD_Id(SPA_META_Header),
                                SPA_PARAM_META_size, SPA_POD_Int(sizeof(struct spa_meta_header)));
                        break;
                case 1:
                        param = spa_pod_builder_add_object(&b,
                                SPA_TYPE_OBJECT_ParamMeta, id,
                                SPA_PARAM_META_type, SPA_POD_Id(SPA_META_VideoDamage),
                                SPA_PARAM_META_size, SPA_POD_Int(sizeof(struct spa_meta_region)));
                        break;
                default:
                        return 0;
                }
                break;
 
        case SPA_PARAM_IO:
                switch (result.index) {
                case 0:
                        param = spa_pod_builder_add_object(&b,
                                SPA_TYPE_OBJECT_ParamIO, id,
                                SPA_PARAM_IO_id,   SPA_POD_Id(SPA_IO_Buffers),
                                SPA_PARAM_IO_size, SPA_POD_Int(sizeof(struct spa_io_buffers)));
                        break;
                case 1:
                        param = spa_pod_builder_add_object(&b,
                                SPA_TYPE_OBJECT_ParamIO, id,
                                SPA_PARAM_IO_id,   SPA_POD_Id(SPA_IO_Notify),
                                SPA_PARAM_IO_size, SPA_POD_Int(sizeof(struct spa_io_sequence) + 1024));
                        break;
                default:
                        return 0;
                }
                break;
        default:
                return -ENOENT;
        }
 
        if (spa_pod_filter(&b, &result.param, param, filter) < 0)
                goto next;
 
        spa_node_emit_result(&d->hooks, seq, 0, SPA_RESULT_TYPE_NODE_PARAMS, &result);
 
        if (++count != num)
                goto next;
 
        return 0;
}
 
static int port_set_format(void *object,
                           enum spa_direction direction, uint32_t port_id,
                           uint32_t flags, const struct spa_pod *format)
{
        struct data *d = object;
        Uint32 sdl_format;
        void *dest;
 
        if (format == NULL) {
                spa_zero(d->format);
                SDL_DestroyTexture(d->texture);
                d->texture = NULL;
        } else {
                spa_debug_format(0, NULL, format);
 
                spa_format_video_raw_parse(format, &d->format);
 
                sdl_format = id_to_sdl_format(d->format.format);
                if (sdl_format == SDL_PIXELFORMAT_UNKNOWN)
                        return -EINVAL;
                if (d->format.size.width == 0 ||
                    d->format.size.height == 0)
                        return -EINVAL;
 
                d->texture = SDL_CreateTexture(d->renderer,
                                                  sdl_format,
                                                  SDL_TEXTUREACCESS_STREAMING,
                                                  d->format.size.width,
                                                  d->format.size.height);
                SDL_LockTexture(d->texture, NULL, &dest, &d->stride);
                SDL_UnlockTexture(d->texture);
 
        }
        d->info.change_mask = SPA_PORT_CHANGE_MASK_PARAMS;
        if (format) {
                d->params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_READWRITE);
                d->params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, SPA_PARAM_INFO_READ);
        } else {
                d->params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
                d->params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
        }
 
        spa_node_emit_port_info(&d->hooks, direction, port_id, &d->info);
        d->info.change_mask = 0;
 
        return 0;
}
 
static int impl_port_set_param(void *object,
                               enum spa_direction direction, uint32_t port_id,
                               uint32_t id, uint32_t flags,
                               const struct spa_pod *param)
{
        if (id == SPA_PARAM_Format) {
                return port_set_format(object, direction, port_id, flags, param);
        }
        else
                return -ENOENT;
}
 
static int impl_port_use_buffers(void *object,
                enum spa_direction direction, uint32_t port_id,
                uint32_t flags,
                struct spa_buffer **buffers, uint32_t n_buffers)
{
        struct data *d = object;
        uint32_t i;
 
        if (n_buffers > MAX_BUFFERS)
                return -ENOSPC;
 
        for (i = 0; i < n_buffers; i++)
                d->buffers[i] = buffers[i];
        d->n_buffers = n_buffers;
        return 0;
}
 
static int do_render(struct spa_loop *loop, bool async, uint32_t seq,
                     const void *_data, size_t size, void *user_data)
{
        struct data *d = user_data;
        const struct spa_buffer *buf = *(struct spa_buffer**)_data;
        uint8_t *map;
        void *sdata, *ddata;
        int sstride, dstride, ostride;
        uint32_t i;
        uint8_t *src, *dst;
        struct spa_meta *m;
        struct spa_meta_region *r;
 
        handle_events(d);
 
        if (buf->datas[0].type == SPA_DATA_MemFd ||
            buf->datas[0].type == SPA_DATA_DmaBuf) {
                map = mmap(NULL, buf->datas[0].maxsize + buf->datas[0].mapoffset, PROT_READ,
                           MAP_PRIVATE, buf->datas[0].fd, 0);
                sdata = SPA_PTROFF(map, buf->datas[0].mapoffset, uint8_t);
        } else if (buf->datas[0].type == SPA_DATA_MemPtr) {
                map = NULL;
                sdata = buf->datas[0].data;
        } else
                return -EINVAL;
 
        if (SDL_LockTexture(d->texture, NULL, &ddata, &dstride) < 0) {
                fprintf(stderr, "Couldn't lock texture: %s\n", SDL_GetError());
                return -EIO;
        }
 
        if ((m = spa_buffer_find_meta(buf, SPA_META_VideoDamage))) {
                spa_meta_for_each(r, m) {
                        if (!spa_meta_region_is_valid(r))
                                break;
                        if (memcmp(&r->region, &d->region, sizeof(struct spa_region)) == 0)
                                break;
                        d->region = r->region;
                        fprintf(stderr, "region %dx%d->%dx%d\n",
                                        r->region.position.x, r->region.position.y,
                                        r->region.size.width, r->region.size.height);
                }
        }
 
        sstride = buf->datas[0].chunk->stride;
        ostride = SPA_MIN(sstride, dstride);
 
        src = sdata;
        dst = ddata;
        for (i = 0; i < d->format.size.height; i++) {
                memcpy(dst, src, ostride);
                src += sstride;
                dst += dstride;
        }
        SDL_UnlockTexture(d->texture);
 
        SDL_RenderClear(d->renderer);
        SDL_RenderCopy(d->renderer, d->texture, NULL, NULL);
        SDL_RenderPresent(d->renderer);
 
        if (map)
                munmap(map, buf->datas[0].maxsize + buf->datas[0].mapoffset);
 
        return 0;
}
 
static int impl_node_process(void *object)
{
        struct data *d = object;
        struct spa_buffer *buf;
        int res;
 
        if (d->io->status != SPA_STATUS_HAVE_DATA)
                return SPA_STATUS_NEED_DATA;
 
        if (d->io->buffer_id >= d->n_buffers)
                return SPA_STATUS_NEED_DATA;
 
        buf = d->buffers[d->io->buffer_id];
 
        if ((res = pw_loop_invoke(pw_main_loop_get_loop(d->loop), do_render,
                                  SPA_ID_INVALID, &buf, sizeof(struct spa_buffer *),
                                  false, d)) < 0)
                return res;
 
        update_param(d);
 
        return d->io->status = SPA_STATUS_NEED_DATA;
}
 
static const struct spa_node_methods impl_node = {
        SPA_VERSION_NODE_METHODS,
        .add_listener = impl_add_listener,
        .set_callbacks = impl_set_callbacks,
        .set_io = impl_set_io,
        .send_command = impl_send_command,
        .port_set_io = impl_port_set_io,
        .port_enum_params = impl_port_enum_params,
        .port_set_param = impl_port_set_param,
        .port_use_buffers = impl_port_use_buffers,
        .process = impl_node_process,
};
 
static void make_node(struct data *data)
{
        struct pw_properties *props;
 
        props = pw_properties_new(PW_KEY_NODE_AUTOCONNECT, "true", NULL);
        if (data->path)
                pw_properties_set(props, PW_KEY_TARGET_OBJECT, data->path);
        pw_properties_set(props, PW_KEY_MEDIA_CLASS, "Stream/Input/Video");
        pw_properties_set(props, PW_KEY_MEDIA_TYPE, "Video");
        pw_properties_set(props, PW_KEY_MEDIA_CATEGORY, "Capture");
        pw_properties_set(props, PW_KEY_MEDIA_ROLE, "Camera");
 
        data->impl_node.iface = SPA_INTERFACE_INIT(
                        SPA_TYPE_INTERFACE_Node,
                        SPA_VERSION_NODE,
                        &impl_node, data);
        pw_core_export(data->core, SPA_TYPE_INTERFACE_Node,
                        &props->dict, &data->impl_node, 0);
        pw_properties_free(props);
}
 
static void set_permissions(struct data *data)
{
        struct pw_permission permissions[2];
 
        /* an example, set specific permissions on one object, this is the
         * core object. */
        permissions[0] = PW_PERMISSION_INIT(PW_ID_CORE, PW_PERM_R | PW_PERM_X);
        /* remove WX from all other objects */
        permissions[1] = PW_PERMISSION_INIT(PW_ID_ANY, PW_PERM_R);
 
        pw_client_update_permissions(
                        pw_core_get_client(data->core),
                        2, permissions);
}
 
static void on_core_error(void *data, uint32_t id, int seq, int res, const char *message)
{
        struct data *d = data;
 
        pw_log_error("error id:%u seq:%d res:%d (%s): %s",
                        id, seq, res, spa_strerror(res), message);
 
        if (id == PW_ID_CORE)
                pw_main_loop_quit(d->loop);
}
 
static const struct pw_core_events core_events = {
        PW_VERSION_CORE_EVENTS,
        .error = on_core_error,
};
 
int main(int argc, char *argv[])
{
        struct data data = { 0, };
 
        pw_init(&argc, &argv);
 
        data.loop = pw_main_loop_new(NULL);
        data.context = pw_context_new(pw_main_loop_get_loop(data.loop), NULL, 0);
        data.path = argc > 1 ? argv[1] : NULL;
 
        spa_hook_list_init(&data.hooks);
 
        data.info = SPA_PORT_INFO_INIT();
        data.info.change_mask = SPA_PORT_CHANGE_MASK_FLAGS;
        data.info.flags = 0;
        data.info.change_mask |= SPA_PORT_CHANGE_MASK_PARAMS;
        data.params[0] = SPA_PARAM_INFO(SPA_PARAM_EnumFormat, SPA_PARAM_INFO_READ);
        data.params[1] = SPA_PARAM_INFO(SPA_PARAM_Meta, SPA_PARAM_INFO_READ);
        data.params[2] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
        data.params[3] = SPA_PARAM_INFO(SPA_PARAM_Buffers, SPA_PARAM_INFO_READ);
        data.params[4] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
        data.info.params = data.params;
        data.info.n_params = 5;
 
        reset_props(&data.props);
 
        if (SDL_Init(SDL_INIT_VIDEO) < 0) {
                printf("can't initialize SDL: %s\n", SDL_GetError());
                return -1;
        }
 
        if (SDL_CreateWindowAndRenderer
            (WIDTH, HEIGHT, SDL_WINDOW_RESIZABLE, &data.window, &data.renderer)) {
                printf("can't create window: %s\n", SDL_GetError());
                return -1;
        }
 
        data.core = pw_context_connect(data.context, NULL, 0);
        if (data.core == NULL) {
                printf("can't connect: %m\n");
                return -1;
        }
        pw_core_add_listener(data.core, &data.core_listener, &core_events, &data);
 
        set_permissions(&data);
 
        make_node(&data);
 
        pw_main_loop_run(data.loop);
 
        pw_context_destroy(data.context);
        pw_main_loop_destroy(data.loop);
 
        return 0;
}