mplay.mp3

commit 59883095b00ba55ce7441a22e8de6971059e0041
parent ac7ab7067e81f8ab3748de26acefc4c8f31ec8ea
Author: Louis Burda <quent.burda@gmail.com>
Date:   Wed, 13 Mar 2024 20:34:43 +0100

Let minimp3 handle file mapping and extracting mp3 metadata

Diffstat:
M
mplay.mp3.c
 | 
177
++++++++++++++++---------------------------------------------------------------

1 file changed, 35 insertions(+), 142 deletions(-)
diff --git a/mplay.mp3.c b/mplay.mp3.c
@@ -1,7 +1,7 @@
 #include "mplay.h"
 
 #define MINIMP3_IMPLEMENTATION
-#include "minimp3.h"
+#include "minimp3_ex.h"
 
 #include <pulse/sample.h>
 #include <pulse/introspect.h>
@@ -25,38 +25,20 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-struct audiofile {
-	uint8_t *data;
-	size_t len;
-};
-
 struct decoder {
-	mp3dec_t dec;
-	uint8_t *pos;
-	ssize_t left;
-
-	mp3d_sample_t *samples;
-	size_t sample_cnt;
-	size_t sample_cap;
-	size_t sample_max;
-
+	mp3dec_ex_t dec;
 	size_t sample_next;
-
-	bool seek;
+	size_t samples_max;
+	size_t samples_read;
 
 	int rate;
 	int channels;
 
+	bool seek;
 	bool init;
 	bool pause;
 };
 
-static pa_sample_spec pa_spec = {
-	.format = PA_SAMPLE_S16LE,
-	.rate = 44100,
-	.channels = 2
-};
-
 static pa_buffer_attr pa_buf = {
 	.fragsize = UINT32_MAX,
 	.maxlength = UINT32_MAX,
@@ -74,8 +56,6 @@ static pa_stream *pa_strm;
 static pa_sink_input_info pa_strm_sink;
 static bool pa_strm_sink_update;
 
-static struct audiofile audiofile = { 0 };
-
 static struct decoder decoder = { 0 };
 
 static pthread_t input_worker_thread;
@@ -139,99 +119,18 @@ get_line(char *buf, int size)
 	if (istty) term_set_raw();
 }
 
-static uint8_t *
-map_file(const char *path, size_t *len)
-{
-	struct stat attr;
-	uint8_t *buf;
-	int fd;
-
-	fd = open(path, O_RDONLY);
-	if (fd < 0) die("open %s:", path);
-
-	if (fstat(fd, &attr))
-		die("fstat %s:", path);
-
-	if ((attr.st_mode & S_IFMT) == S_IFDIR)
-		die("not a file: %s", path);
-
-	buf = mmap(NULL, (size_t) attr.st_size, PROT_READ, MAP_SHARED, fd, 0);
-	if (!buf) die("mmap %s:", path);
-
-	*len = (size_t) attr.st_size;
-
-	close(fd);
-
-	return buf;
-}
-
-static size_t
-decode_next_frame(mp3d_sample_t *samples, size_t *size)
-{
-	static const size_t max_cnt = MINIMP3_MAX_SAMPLES_PER_FRAME;
-	mp3dec_frame_info_t info;
-	size_t cnt;
-
-	if (size) *size = 0;
-
-	if (decoder.sample_next < decoder.sample_cnt) {
-		cnt = MIN(max_cnt, decoder.sample_cnt - decoder.sample_next);
-		*size = cnt * sizeof(mp3d_sample_t);
-	} else {
-		if (decoder.sample_cnt + max_cnt > decoder.sample_cap) {
-			decoder.sample_cap = MAX(decoder.sample_cap * 2,
-				decoder.sample_cnt + max_cnt);
-			decoder.samples = realloc(decoder.samples,
-				decoder.sample_cap * sizeof(mp3d_sample_t));
-			if (!decoder.samples) die("realloc:");
-		}
-
-		cnt = (size_t) mp3dec_decode_frame(&decoder.dec, decoder.pos,
-			(int) decoder.left, &decoder.samples[decoder.sample_cnt], &info);
-		cnt *= (size_t) info.channels;
-		decoder.sample_cnt += cnt;
-
-		if (size) *size = (size_t) info.frame_bytes;
-
-		if (!info.frame_bytes)
-			return 0;
-
-		if (!decoder.init) {
-			decoder.rate = info.hz;
-			decoder.channels = info.channels;
-		}
-
-		decoder.pos += info.frame_bytes;
-		decoder.left -= info.frame_bytes;
-	}
-
-	if (samples != NULL)
-		memcpy(samples, &decoder.samples[decoder.sample_next],
-			cnt * sizeof(mp3d_sample_t));
-	decoder.sample_next += cnt;
-
-	return cnt;
-}
-
 static void
-decoder_init(void)
+decoder_init(const char *filepath)
 {
-	mp3d_sample_t samples[MINIMP3_MAX_SAMPLES_PER_FRAME];
-	size_t size;
-
-	mp3dec_init(&decoder.dec);
-	decoder.pos = audiofile.data;
-	decoder.left = (ssize_t) audiofile.len;
+	if (mp3dec_ex_open(&decoder.dec, filepath, MP3D_SEEK_TO_SAMPLE))
+		die("mp3dec_ex_open");
 
-	decoder.sample_cnt = 0;
 	decoder.sample_next = 0;
-	decoder.sample_cap = MINIMP3_MAX_SAMPLES_PER_FRAME;
-	decoder.samples = malloc(decoder.sample_cap * sizeof(mp3d_sample_t));
-	if (!decoder.samples) die("malloc:");
+	decoder.samples_max = 0;
+	decoder.samples_max = decoder.dec.samples / (size_t)decoder.dec.info.channels;
 
-	/* decode channel specs */
-	decode_next_frame(samples, &size);
-	if (!size) die("invalid mp3");
+	decoder.channels = decoder.dec.info.channels;
+	decoder.rate = decoder.dec.info.hz;
 
 	decoder.seek = false;
 	decoder.pause = false;
@@ -241,15 +140,7 @@ decoder_init(void)
 static void
 decoder_seek(size_t sample_pos)
 {
-	size_t size, cnt;
-
-	while (decoder.sample_next < sample_pos) {
-		cnt = decode_next_frame(NULL, &size);
-		if (!size) {
-			mplay_status(MPLAY_INFO_EXIT, "from seek");
-			exit(0);
-		}
-	}
+	mp3dec_ex_seek(&decoder.dec, sample_pos * (size_t)decoder.channels);
 	decoder.sample_next = sample_pos;
 }
 
@@ -263,28 +154,31 @@ pa_stream_drain_callback(pa_stream *stream, int success, void *data)
 static void
 pa_stream_write_callback(pa_stream *stream, size_t requested, void *data)
 {
-	mp3d_sample_t samples[MINIMP3_MAX_SAMPLES_PER_FRAME];
+	mp3dec_frame_info_t info;
+	mp3d_sample_t *samples;
 	pa_operation *op;
 	ssize_t remaining;
-	size_t cnt, size;
+	size_t cnt;
 
 	remaining = (ssize_t) requested;
 	while (remaining > 0) {
-		cnt = decode_next_frame(samples, &size);
-		if (!size) {
+		cnt = mp3dec_ex_read_frame(&decoder.dec, &samples, &info, requested);
+		if (!cnt) {
 			op = pa_stream_drain(pa_strm,
 				pa_stream_drain_callback, NULL);
 			pa_operation_unref(op);
 			return;
 		}
-		if (!cnt) continue;
 
 		pa_stream_write(stream, samples,
 			cnt * sizeof(mp3d_sample_t), NULL, 0,
 			decoder.seek ? PA_SEEK_RELATIVE_ON_READ: PA_SEEK_RELATIVE);
 
 		decoder.seek = false;
-		remaining -= (ssize_t) (cnt * sizeof(mp3d_sample_t));
+		decoder.sample_next += cnt / (size_t)decoder.channels;
+		decoder.samples_read = decoder.sample_next;
+		decoder.samples_max = MAX(decoder.samples_max, decoder.samples_read);
+		remaining -= (ssize_t) (cnt * (size_t)decoder.channels * sizeof(mp3d_sample_t));
 	}
 }
 
@@ -347,7 +241,7 @@ stream_samples_buffered(void)
 		last_write_index = (size_t) MAX(0, info->write_index);
 
 	buffered = (last_write_index - last_read_index)
-		/ sizeof(mp3d_sample_t);
+		/ ((size_t) decoder.channels * sizeof(mp3d_sample_t));
 
 	last_read_index = (size_t) MAX(0, info->read_index);
 
@@ -371,19 +265,19 @@ user_vol(void)
 static double
 user_pos(void)
 {
-	size_t sample_pos;
+	ssize_t sample_pos;
 
-	sample_pos = (size_t) MAX(0,
-		(ssize_t) decoder.sample_next - (ssize_t) stream_samples_buffered());
+	sample_pos = (ssize_t) decoder.samples_read;
+	sample_pos -= (ssize_t) stream_samples_buffered();
+	sample_pos = MAX(0, sample_pos);
 
-	return (double) sample_pos * 1.F / (double) (decoder.rate * decoder.channels);
+	return (double) sample_pos * 1.F / (double) decoder.rate;
 }
 
 static double
 user_end(void)
 {
-	return (double) decoder.sample_max * 1.F
-		/ (double) (decoder.rate * decoder.channels);
+	return (double) decoder.samples_max * 1.F / (double) decoder.rate;
 }
 
 static void
@@ -577,8 +471,13 @@ static void
 pulse_stream_init(void)
 {
 	pa_channel_map pa_chmap;
+	pa_sample_spec pa_spec;
 	int ret;
 
+	pa_spec.format = PA_SAMPLE_S16LE;
+	pa_spec.channels = (uint8_t) decoder.channels;
+	pa_spec.rate = (uint32_t) decoder.rate;
+
 	pa_channel_map_init_stereo(&pa_chmap);
 
 	pa_strm = pa_stream_new(pa_ctx, "mplay.mp3", &pa_spec, &pa_chmap);
@@ -622,8 +521,6 @@ cleanup(void)
 	pa_context_disconnect(pa_ctx);
 	pa_context_unref(pa_ctx);
 
-	munmap(audiofile.data, audiofile.len);
-
 	if (input_worker_alive)
 		pthread_kill(input_worker_thread, SIGINT);
 }
@@ -657,11 +554,7 @@ main(int argc, const char **argv)
 
 	istty = isatty(0);
 
-	audiofile.data = map_file(file, &audiofile.len);
-	decoder_init();
-
-	pa_spec.channels = (uint8_t) decoder.channels;
-	pa_spec.rate = (uint32_t) decoder.rate;
+	decoder_init(file);
 
 	pa_mloop = pa_threaded_mainloop_new();
 	if (!pa_mloop) die("pa_threaded_mainloop_new");