examples: Use new fps limiter in videoplayer example

examples/videoplayer/Makefile

@@ -24,7 +24,7 @@ filesystem/movie.m1v: $(MOVIE_FILE)
 	@mkdir -p "$(dir $@)"
 	if [ -s "$<" ]; then \
 		if command -v ffmpeg; then \
-			ffmpeg -y -i "$<" -vb 800K -vf 'scale=320x176' -r 20 "$@" ; \
+			ffmpeg -y -i "$<" -vb 800K -vf 'scale=288x160' -r 24 "$@" ; \
 		else \
 			echo "videoplayer: Skipping video re-encoding because ffmpeg is not installed" ; \
 			touch "$@" ; \

examples/videoplayer/videoplayer.c

@@ -1,98 +1,121 @@
 #include <libdragon.h>
 #include "../../src/video/profile.h"
 
-#define NUM_DISPLAY   8
-
-void audio_poll(void) {	
-	if (audio_can_write()) {    	
-		PROFILE_START(PS_AUDIO, 0);
-		short *buf = audio_write_begin();
-		mixer_poll(buf, audio_get_buffer_length());
-		audio_write_end();
-		PROFILE_STOP(PS_AUDIO, 0);
-	}
-}
-
-void video_poll(void) {
-
-
-}
-
-int main(void) {
+// Number of frame back buffers we reserve.
+// These buffers are used to render the video ahead of time.
+// More buffers help ensure smooth video playback at the cost of more memory.
+#define NUM_DISPLAY 8
+
+// Maximum target audio frequency.
+//
+// Needs to be 48 kHz if Opus audio compression is used.
+// In this example, we are using VADPCM audio compression
+// which means we can use the real frequency of the audio track.
+#define AUDIO_HZ 32000.0f
+
+// Target screen resolution that we render at.
+// Choosing a resolution above 240p (interlaced) can't be recommended for video playback.
+#define SCREEN_WIDTH 320
+#define SCREEN_HEIGHT 240
+
+int main(void)
+{
 	joypad_init();
 	debug_init_isviewer();
 	debug_init_usblog();
 
-	display_init(RESOLUTION_320x240, DEPTH_32_BPP, NUM_DISPLAY, GAMMA_NONE, FILTERS_DISABLED);
+	display_init((resolution_t)
+	{
+		.width = SCREEN_WIDTH,
+		.height = SCREEN_HEIGHT,
+		.interlaced = INTERLACE_OFF
+	},
+	// 32-bit display mode is mandatory for video playback.
+	DEPTH_32_BPP,
+	NUM_DISPLAY, GAMMA_NONE,
+	// FILTERS_DISABLED disables all VI post-processing to achieve the sharpest
+	// possible image. If you'd like to soften the image a little bit, switch to
+	// FITLERS_RESAMPLE.
+	FILTERS_DISABLED);
+
 	dfs_init(DFS_DEFAULT_LOCATION);
 	rdpq_init();
 	profile_init();
 	yuv_init();
 
-	audio_init(44100, 4);
+	audio_init(AUDIO_HZ, 4);
 	mixer_init(8);
 
 	// Check if the movie is present in the filesystem, so that we can provide
-	// a specific error message
+	// a specific error message.
 	FILE *f = fopen("rom:/movie.m1v", "rb");
 	assertf(f, "Movie not found!\nInstall wget and ffmpeg to download and encode the sample movie\n");
 	fclose(f);
 
-	mpeg2_t *mp2 = mpeg2_open("rom:/movie.m1v");
-
-	// Create a YUV blitter to draw this movie
+	// Open the movie using the mpeg2 module and create a YUV blitter to draw it.
+	mpeg2_t* video_track = mpeg2_open("rom:/movie.m1v");
 	yuv_blitter_t yuv = yuv_blitter_new_fmv(
-		mpeg2_get_width(mp2), mpeg2_get_height(mp2),		// Video size
-		display_get_width(), display_get_height(),			// Output size
-		NULL												// Colorspace (use default)
-	);												
-
-	wav64_t music;
-	wav64_open(&music, "movie.wav64");
-
-	float fps = mpeg2_get_framerate(mp2);
-	throttle_init(fps, 0, 8);
-
-	mixer_ch_play(0, &music.wave);
+		// Resolution of the video we expect to play.
+		// Video needs to have a width divisible by 32 and a height divisible by 16.
+		//
+		// Here we have a video resolution of 288x160 which is a nice, valid resolution
+		// that leaves a margin of 32 pixels on the side - great for making sure
+		// CRT TVs with overscan still display the entire frame of your video.
+		// The resolution is not an exact 16:9 ratio (16:8.88) but it's close enough that
+		// most people won't notice. The lower resolution can also help with performance.
+		mpeg2_get_width(video_track), mpeg2_get_height(video_track),
+		// Set blitter's output area to our entire display
+		display_get_width(), display_get_height(),
+		// Override default FMV parms to not zoom the video.
+		// This will leave our desired CRT TV-friendly margin around the video.
+		&(yuv_fmv_parms_t) {.zoom = YUV_ZOOM_NONE}
+	);
+
+	// Engage the fps limiter to ensure proper video pacing.
+	float fps = mpeg2_get_framerate(video_track);
+	display_set_fps_limit(fps);
+
+	// Open the audio track and start playing it in channel 0.
+	wav64_t audio_track;
+	wav64_open(&audio_track, "movie.wav64");
+	mixer_ch_play(0, &audio_track.wave);
 
 	int nframes = 0;
-	display_context_t disp = 0;
 
-	while (1) {
-		mixer_throttle(44100.0f / fps);
+	while (1)
+	{
+		mixer_throttle(AUDIO_HZ / fps);
 
-		if (!mpeg2_next_frame(mp2))
+		if (!mpeg2_next_frame(video_track))
+		{
 			break;
+		}
 
-		disp = display_get();
+		// This polls the mixer to try and play the next chunk of audio, if available.
+		// We call this function twice during the frame to make sure the audio never stalls.
+		mixer_try_play();
 
-		// rdpq_attach(disp, NULL);
-		rdpq_attach_clear(disp, NULL);
+		rdpq_attach(display_get(), NULL);
 
 		PROFILE_START(PS_YUV, 0);
-		yuv_frame_t frame = mpeg2_get_frame(mp2);
+		// Get the next video frame and feed it into our previously set up blitter.
+		yuv_frame_t frame = mpeg2_get_frame(video_track);
 		yuv_blitter_run(&yuv, &frame);
 		PROFILE_STOP(PS_YUV, 0);
 
 		rdpq_detach_show();
 
-		audio_poll();
-
 		nframes++;
 
-		int ret = throttle_wait();
-		if (ret < 0) {
-			debugf("videoplayer: frame %d too slow (%d Kcycles)\n", nframes, -ret);
-		}
-
-		audio_poll();
+		mixer_try_play();
 
 		PROFILE_START(PS_SYNC, 0);
 		rspq_wait();
 		PROFILE_STOP(PS_SYNC, 0);
 
 		profile_next_frame();
-		if (nframes % 128 == 0) {
+		if (nframes % 128 == 0)
+		{
 			profile_dump();
 			profile_init();
 		}