actual video recording is workign!

3 files changed, 73 insertions, 27 deletions

diff --git a/camera.c b/camera.c
index 74434c8..b9b2200 100644
--- a/camera.c
+++ b/camera.c
@@ -10,6 +10,7 @@
 #include "ds.h"
 #include "3rd_party/stb_image_write.h"
 #include <jpeglib.h>
+#include <libavcodec/avcodec.h>
 
 #define CAMERA_MAX_BUFFERS 4
 struct Camera {
@@ -925,3 +926,36 @@ void camera_hash_str(Camera *camera, char str[HASH_SIZE * 2 + 1]) {
 const char *camera_devnode(Camera *camera) {
 	return camera->devnode;
 }
+
+bool camera_copy_to_av_frame(Camera *camera, struct AVFrame *frame_out) {
+	uint8_t *frame_in = camera_curr_frame(camera);
+	int32_t frame_width = camera_frame_width(camera);
+	int32_t frame_height = camera_frame_height(camera);
+	if (!frame_in
+		|| frame_width != frame_out->width
+		|| frame_height != frame_out->height
+		|| camera_pixel_format(camera) != V4L2_PIX_FMT_YUV420
+		|| frame_out->format != AV_PIX_FMT_YUV420P) {
+		return false;
+	}
+	// copy Y plane
+	for (int64_t y = 0; y < frame_height; y++) {
+		memcpy(&frame_out->data[0][y * frame_out->linesize[0]],
+			&frame_in[y * frame_width], frame_width);
+	}
+	// copy Cb plane
+	int64_t cb_offset = (int64_t)frame_width * frame_height;
+	for (int64_t y = 0; y < frame_height / 2; y++) {
+		memcpy(&frame_out->data[1][y * frame_out->linesize[1]],
+			&frame_in[cb_offset + y * (frame_width / 2)],
+			frame_width / 2);
+	}
+	// copy Cr plane
+	int64_t cr_offset = cb_offset + (int64_t)frame_width / 2 * frame_height / 2;
+	for (int64_t y = 0; y < frame_height / 2; y++) {
+		memcpy(&frame_out->data[2][y * frame_out->linesize[2]],
+			&frame_in[cr_offset + y * (frame_width / 2)],
+			frame_width / 2);
+	}
+	return true;
+}
diff --git a/camera.h b/camera.h
index 0ea646d..56f30ee 100644
--- a/camera.h
+++ b/camera.h
@@ -6,6 +6,7 @@
 #include <stddef.h>
 #include <string.h>
 #include <GL/glcorearb.h>
+struct AVFrame;
 
 typedef uint32_t PixelFormat;
 typedef struct Camera Camera;
@@ -127,6 +128,10 @@ bool camera_open(Camera *camera);
 Hash camera_hash(Camera *camera);
 void camera_hash_str(Camera *camera, char str[HASH_SIZE * 2 + 1]);
 bool camera_set_format(Camera *camera, PictureFormat picfmt, CameraAccessMethod access, bool force);
+/// Copy current frame from camera to AVFrame.
+///
+/// Returns `true` on success. Currently only works if both the camera and the AVFrame are in the YUV420 format.
+bool camera_copy_to_av_frame(Camera *camera, struct AVFrame *frame);
 void camera_free(Camera *camera);
 
 #endif
diff --git a/main.c b/main.c
index 72527bd..2a1bb56 100644
--- a/main.c
+++ b/main.c
@@ -88,6 +88,7 @@ typedef struct {
 	bool quit;
 	CameraMode mode;
 	bool recording_video;
+	double video_start_time;
 	AVFormatContext *avf_context;
 	AVCodecContext *video_encoder;
 	AVFrame *video_frame;
@@ -591,7 +592,6 @@ static bool write_frame(State *state, AVCodecContext *encoder, AVStream *stream,
 	return true;
 }
 
-
 static void stop_video(State *state) {
 	if (state->recording_video) {
 		state->recording_video = false;
@@ -651,11 +651,13 @@ static bool start_video(State *state, const char *filename) {
 		return false;
 	}
 	state->video_encoder->codec_id = fmt->video_codec;
-	// TODO: adjustable video framerate
-	state->video_encoder->bit_rate = (int64_t)5 * camera_frame_width(state->camera) * camera_frame_height(state->camera);
+	// TODO: adjustable video quality
+	const int64_t quality = 5;
+	state->video_encoder->bit_rate = quality * camera_frame_width(state->camera) * camera_frame_height(state->camera);
 	state->video_encoder->width = camera_frame_width(state->camera);
 	state->video_encoder->height = camera_frame_height(state->camera);
-	state->video_encoder->time_base = state->video_stream->time_base = (AVRational){1,30};// TODO: restrict application to 30FPS when recording video
+	// TODO: adjustable video framerate
+	state->video_encoder->time_base = state->video_stream->time_base = (AVRational){1,30};
 	state->video_encoder->gop_size = 12;
 	state->video_encoder->pix_fmt = AV_PIX_FMT_YUV420P;
 	if (state->avf_context->oformat->flags & AVFMT_GLOBALHEADER)
@@ -695,23 +697,7 @@ static bool start_video(State *state, const char *filename) {
 		return false;
 	}
 	state->recording_video = true;
-	// ----
-	for (int frame = 0; frame < 300; frame++) {
-	err = av_frame_make_writable(state->video_frame);
-	if (err < 0) {
-		fprintf(stderr, "error: av_frame_make_writable: %s\n", av_err2str(err));
-		return false;
-	}
-	for (int y = 0; y < state->video_frame->height; y++) {
-		for (int x = 0; x < state->video_frame->width; x++) {
-			state->video_frame->data[0][y * state->video_frame->linesize[0] + x] = (uint8_t)(x + y+frame);
-			state->video_frame->data[1][(y/2) * state->video_frame->linesize[1] + x/2] = (uint8_t)(x * y);
-			state->video_frame->data[2][(y/2) * state->video_frame->linesize[2] + x/2] = (uint8_t)(x - y);
-		}
-	}
-	state->video_frame->pts = state->video_pts++;
-	write_frame(state, state->video_encoder, state->video_stream, state->video_frame);
-	}
+	state->video_start_time = get_time_double();
 	return true;
 }
 
@@ -1001,10 +987,10 @@ void main() {\n\
 	o_color = vec4(mix(color, vec3(1.0), u_flash), opacity);\n\
 }\n\
 ";
-	char err[256] = {0};
-	GLuint program = gl_compile_and_link_shaders(err, vshader_code, fshader_code);
-	if (*err) {
-		fatal_error("Couldn't compile shader: %s", err);
+	static char shader_err[256] = {0};
+	GLuint program = gl_compile_and_link_shaders(shader_err, vshader_code, fshader_code);
+	if (*shader_err) {
+		fatal_error("Couldn't compile shader: %s", shader_err);
 	}
 	if (program == 0) {
 		fatal_error("Couldn't compile shader (no error log available)");
@@ -1150,6 +1136,7 @@ void main() {\n\
 				}
 				break;
 			case SDLK_TAB:
+				if (state->recording_video) break;
 				state->mode = (state->mode + 1) % MODE_COUNT;
 				switch (state->mode) {
 				case MODE_PICTURE:
@@ -1416,7 +1403,9 @@ void main() {\n\
 				const char *text[] = {
 					"F1 - open this help screen",
 					"F2 - show debug info",
-					"Space - take a picture",
+					state->mode == MODE_VIDEO
+						? "Space - start/stop recording"
+						: "Space - take a picture",
 					"Escape - open/close settings",
 					"Ctrl+f - open picture directory",
 					"Tab - switch between picture and video",
@@ -1493,6 +1482,23 @@ void main() {\n\
 				last_camera_time = curr_time;
 				n_active_textures = camera_update_gl_textures(state->camera, camera_textures);
 			}
+			if (state->recording_video) {
+				int64_t next_pts = state->video_pts;
+				int64_t curr_pts = (int64_t)((curr_time - state->video_start_time)
+					* state->video_encoder->time_base.den
+					/ state->video_encoder->time_base.num);
+				if (curr_pts >= next_pts) {
+					int err = av_frame_make_writable(state->video_frame);
+					if (err < 0) {
+						fprintf(stderr, "error: av_frame_make_writable: %s\n", av_err2str(err));
+						return EXIT_FAILURE;
+					}
+					state->video_frame->pts = curr_pts;
+					camera_copy_to_av_frame(state->camera, state->video_frame);
+					write_frame(state, state->video_encoder, state->video_stream, state->video_frame);
+					state->video_pts = curr_pts + 1;
+				}
+			}
 			gl.Uniform1i(u_pixel_format, last_frame_pixfmt);
 			gl.ActiveTexture(GL_TEXTURE0);
 			// we always want to bind something to every texture slot,
@@ -1586,7 +1592,7 @@ void main() {\n\
 				SDL_FreeSurface(surf);
 			}
 			gl.Uniform2f(u_scale, gl_width, gl_height);
-			gl.Uniform2f(u_offset, 1 - gl_width, 1 - gl_height);
+			gl.Uniform2f(u_offset, 0.99f - gl_width, 1 - gl_height);
 			gl.Uniform1i(u_sampler, 0);
 			gl.Uniform1f(u_opacity, 1);
 			gl.Uniform1i(u_pixel_format, V4L2_PIX_FMT_RGBA32);
@@ -1650,6 +1656,7 @@ void main() {\n\
 		SDL_GL_SwapWindow(window);
 	}
 	quit:
+	stop_video(state);
 	udev_monitor_unref(udev_monitor);
 	udev_unref(udev);
 	arr_foreach_ptr(state->cameras, Camera *, pcamera) {