Make progress updates depend on wall time instead of progress

Progress updates were output too often on fast CPUs and not often
enough for slow CPUs. In the Windows shell this gave the additional
problem that such output is extremely slow.

See https://hydrogenaud.io/index.php/topic,123014.msg1017724.html#msg1017724

src/flac/decode.c

@@ -25,6 +25,7 @@
 #include <math.h> /* for floor() */
 #include <stdio.h> /* for FILE etc. */
 #include <string.h> /* for strcmp(), strerror() */
+#include <time.h> /* for clock() */
 #include "FLAC/all.h"
 #include "share/grabbag.h"
 #include "share/replaygain_synthesis.h"
@@ -91,6 +92,8 @@ typedef struct {
 
 	foreign_metadata_t *foreign_metadata; /* NULL unless --keep-foreign-metadata requested */
 	FLAC__off_t fm_offset1, fm_offset2, fm_offset3;
+
+	clock_t old_clock_t;
 } DecoderSession;
 
 
@@ -247,6 +250,8 @@ FLAC__bool DecoderSession_construct(DecoderSession *d, FLAC__bool is_ogg, FLAC__
 
 	d->foreign_metadata = foreign_metadata;
 
+	d->old_clock_t = 0;
+
 	FLAC__ASSERT(!(d->test_only && d->analysis_mode));
 
 	if(!d->test_only) {
@@ -1165,8 +1170,16 @@ FLAC__StreamDecoderWriteStatus write_callback(const FLAC__StreamDecoder *decoder
 		decoder_session->samples_processed += wide_samples;
 		decoder_session->frame_counter++;
 
+#if 0 /* in case time.h with clock() isn't available for some reason */
 		if(!(decoder_session->frame_counter & 0x1ff))
 			print_stats(decoder_session);
+#else
+		if((clock() - decoder_session->old_clock_t) > (CLOCKS_PER_SEC/4)) {
+			print_stats(decoder_session);
+			decoder_session->old_clock_t = clock();
+		}
+#endif
+
 
 		if(decoder_session->analysis_mode) {
 			flac__analyze_frame(frame, decoder_session->frame_counter-1, decoder_session->decode_position-frame_bytes, frame_bytes, decoder_session->aopts, fout);

src/flac/encode.c

@@ -27,6 +27,7 @@
 #include <stdio.h> /* for FILE etc. */
 #include <stdlib.h> /* for malloc */
 #include <string.h> /* for strcmp(), strerror() */
+#include <time.h> /* for clock() */
 #include <sys/stat.h>
 #include "FLAC/all.h"
 #include "share/alloc.h"
@@ -89,8 +90,12 @@ typedef struct {
 	FLAC__uint64 unencoded_size; /* an estimate of the input size, only used in the progress indicator */
 	FLAC__uint64 bytes_written;
 	FLAC__uint64 samples_written;
+#if 0 /* in case time.h with clock() isn't available for some reason */
 	uint32_t stats_frames_interval;
 	uint32_t old_frames_written;
+#else
+	clock_t old_clock_t;
+#endif
 
 	SampleInfo info;
 
@@ -1544,8 +1549,12 @@ FLAC__bool EncoderSession_construct(EncoderSession *e, encode_options_t options,
 	e->unencoded_size = 0;
 	e->bytes_written = 0;
 	e->samples_written = 0;
+#if 0 /* in case time.h with clock() isn't available for some reason */
 	e->stats_frames_interval = 0;
 	e->old_frames_written = 0;
+#else
+	e->old_clock_t = 0;
+#endif
 
 	memset(&e->info, 0, sizeof(e->info));
 
@@ -2184,10 +2193,12 @@ FLAC__bool EncoderSession_init_encoder(EncoderSession *e, encode_options_t optio
 	else
 		e->outputfile_opened = true;
 
+#if 0 /* in case time.h with clock() isn't available for some reason */
 	e->stats_frames_interval =
 		(FLAC__stream_encoder_get_do_exhaustive_model_search(e->encoder) && FLAC__stream_encoder_get_do_qlp_coeff_prec_search(e->encoder))? 0x1f :
 		(FLAC__stream_encoder_get_do_exhaustive_model_search(e->encoder) || FLAC__stream_encoder_get_do_qlp_coeff_prec_search(e->encoder))? 0x3f :
 		0xff;
+#endif
 
 	static_metadata_clear(&static_metadata);
 
@@ -2506,7 +2517,7 @@ void encoder_progress_callback(const FLAC__StreamEncoder *encoder, FLAC__uint64
 
 	const FLAC__uint64 uesize = e->unencoded_size;
 
-	(void)encoder, (void)total_frames_estimate;
+	(void)encoder, (void)total_frames_estimate, (void) frames_written;
 
 	e->bytes_written = bytes_written;
 	e->samples_written = samples_written;
@@ -2514,10 +2525,18 @@ void encoder_progress_callback(const FLAC__StreamEncoder *encoder, FLAC__uint64
 	e->progress = e->total_samples_to_encode ? (double)samples_written / (double)e->total_samples_to_encode : 0;
 	e->compression_ratio = (e->progress && uesize) ? (double)e->bytes_written / ((double)uesize * min(1.0, e->progress)) : 0;
 
+#if 0 /* in case time.h with clock() isn't available for some reason */
 	if(e->total_samples_to_encode > 0 && frames_written - e->old_frames_written > e->stats_frames_interval) {
 		print_stats(e);
 		e->old_frames_written = frames_written;
 	}
+#else
+	if(e->total_samples_to_encode > 0 && (clock() - e->old_clock_t) > (CLOCKS_PER_SEC/4)) {
+		print_stats(e);
+		e->old_clock_t = clock();
+	}
+
+#endif
 }
 
 FLAC__StreamDecoderReadStatus flac_decoder_read_callback(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data)