From eab434c416a89a9de30bcca255334eeac97eb433 Mon Sep 17 00:00:00 2001
From: Miika Pekkarinen <miipekk@ihme.org>
Date: Fri, 22 Jul 2005 06:32:55 +0000
Subject: [PATCH] More accurate playback position calculation.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7218 a1c6a512-1295-4272-9138-f99709370657
---
 apps/pcmbuf.c                  | 4 ++--
 apps/playback.c                | 5 +----
 firmware/export/pcm_playback.h | 1 +
 firmware/pcm_playback.c        | 7 ++++++-
 uisimulator/common/stubs.c     | 5 +++++
 5 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/apps/pcmbuf.c b/apps/pcmbuf.c
index cf6911b606..a8769e3829 100644
--- a/apps/pcmbuf.c
+++ b/apps/pcmbuf.c
@@ -202,8 +202,8 @@ unsigned int pcmbuf_get_latency(void)
 {
     int latency;
     
-    /* This has to be done better. */
-    latency = (pcmbuf_size - audiobuffer_free - CHUNK_SIZE)/4 / (44100/1000);
+    latency = (pcmbuf_unplayed_bytes + pcm_get_bytes_waiting())
+                / 4 / (44100/1000);
     if (latency < 0)
         latency = 0;
     
diff --git a/apps/playback.c b/apps/playback.c
index aadb1e289e..7aaff01e54 100644
--- a/apps/playback.c
+++ b/apps/playback.c
@@ -265,10 +265,7 @@ void codec_set_offset_callback(unsigned int value)
     if (ci.stop_codec)
         return ;
         
-    /* The 1000 here is a hack.  pcmbuf_get_latency() should
-     * be more accurate
-     */
-    latency = (pcmbuf_get_latency() + 1000) * cur_ti->id3.bitrate / 8;
+    latency = pcmbuf_get_latency() * cur_ti->id3.bitrate / 8;
     
     if (value < latency) {
         cur_ti->id3.offset = 0;
diff --git a/firmware/export/pcm_playback.h b/firmware/export/pcm_playback.h
index 6222574ed8..3972e45768 100644
--- a/firmware/export/pcm_playback.h
+++ b/firmware/export/pcm_playback.h
@@ -26,6 +26,7 @@ void pcm_set_frequency(unsigned int frequency);
 void pcm_play_data(void (*get_more)(unsigned char** start, long* size));
 
 void pcm_calculate_peaks(int *left, int *right);
+long pcm_get_bytes_waiting(void);
 
 void pcm_play_stop(void);
 void pcm_play_pause(bool play);
diff --git a/firmware/pcm_playback.c b/firmware/pcm_playback.c
index 3a68db4d0c..bafbd8c761 100644
--- a/firmware/pcm_playback.c
+++ b/firmware/pcm_playback.c
@@ -164,7 +164,7 @@ static long calculate_channel_peak_average(int channel, unsigned short *addr,
 void pcm_calculate_peaks(int *left, int *right)
 {
     unsigned short *addr = (unsigned short *)SAR0;
-    long size = MIN(512, BCR0 / 2);
+    long size = MIN(512, (BCR0 & 0xffffff) / 2);
         
     if (left != NULL)
         *left = calculate_channel_peak_average(0, addr, size);
@@ -222,6 +222,11 @@ void pcm_play_data(void (*get_more)(unsigned char** start, long* size))
     uda1380_mute(false);
 }
 
+long pcm_get_bytes_waiting(void)
+{
+    return next_size + (BCR0 & 0xffffff);
+}
+
 void pcm_play_stop(void)
 {
     if (pcm_playing) {
diff --git a/uisimulator/common/stubs.c b/uisimulator/common/stubs.c
index 4ad89e4681..b887fbda83 100644
--- a/uisimulator/common/stubs.c
+++ b/uisimulator/common/stubs.c
@@ -66,6 +66,11 @@ void pcm_play_data(void (*get_more)(unsigned char** start, long* size))
     playing = true;
 }
 
+long pcm_get_bytes_waiting(long)
+{
+    return 0;
+}
+
 #if CONFIG_HWCODEC != MASNONE
 void audio_set_buffer_margin(int seconds)
 {