From fa2f95739a2531b912d054d3ef845e24b796363d Mon Sep 17 00:00:00 2001
From: bnnm <bananaman255@gmail.com>
Date: Fri, 28 Dec 2018 11:04:18 +0100
Subject: [PATCH] Fix AWC MPEG not seeking back correctly

---
 src/coding/mpeg_decoder.c | 42 +++++++++++++++++++++++++--------------
 1 file changed, 27 insertions(+), 15 deletions(-)

diff --git a/src/coding/mpeg_decoder.c b/src/coding/mpeg_decoder.c
index 604e0fa0..37533363 100644
--- a/src/coding/mpeg_decoder.c
+++ b/src/coding/mpeg_decoder.c
@@ -503,24 +503,29 @@ void free_mpeg(mpeg_codec_data *data) {
      * someone else in another thread is using it. */
 }
 
+/* seeks stream to 0 */
 void reset_mpeg(VGMSTREAM *vgmstream) {
     off_t input_offset;
     mpeg_codec_data *data = vgmstream->codec_data;
     if (!data) return;
 
-    /* reset multistream */ //todo check if stream offsets are properly reset
 
     if (!data->custom) {
-        /* input_offset is ignored as we can assume it will be 0 for a seek to sample 0 */
         mpg123_feedseek(data->m,0,SEEK_SET,&input_offset);
+        /* input_offset is ignored as we can assume it will be 0 for a seek to sample 0 */
     }
     else {
         int i;
         /* re-start from 0 */
-        for (i=0; i < data->streams_size; i++) {
+        for (i = 0; i < data->streams_size; i++) {
             mpg123_feedseek(data->streams[i]->m,0,SEEK_SET,&input_offset);
+            data->streams[i]->bytes_in_buffer = 0;
+            data->streams[i]->buffer_full = 0;
+            data->streams[i]->buffer_used = 0;
             data->streams[i]->samples_filled = 0;
             data->streams[i]->samples_used = 0;
+            data->streams[i]->current_size_count = 0;
+            data->streams[i]->current_size_target = 0;
             data->streams[i]->decode_to_discard = 0;
         }
 
@@ -528,29 +533,33 @@ void reset_mpeg(VGMSTREAM *vgmstream) {
     }
 }
 
+/* seeks to a point */
 void seek_mpeg(VGMSTREAM *vgmstream, int32_t num_sample) {
     off_t input_offset;
     mpeg_codec_data *data = vgmstream->codec_data;
     if (!data) return;
 
-    /* seek multistream */
+
     if (!data->custom) {
         mpg123_feedseek(data->m, num_sample,SEEK_SET,&input_offset);
 
-        /* force first offset as discard-looping needs to start from the beginning */
+        /* adjust loop with mpg123's offset (useful?) */
         if (vgmstream->loop_ch)
             vgmstream->loop_ch[0].offset = vgmstream->loop_ch[0].channel_start_offset + input_offset;
     }
     else {
         int i;
         /* re-start from 0 */
-        for (i=0; i < data->streams_size; i++) {
+        for (i = 0; i < data->streams_size; i++) {
             mpg123_feedseek(data->streams[i]->m,0,SEEK_SET,&input_offset);
-            data->streams[i]->samples_filled = 0;
-            data->streams[i]->samples_used = 0;
-            data->streams[i]->decode_to_discard = 0;
+            data->streams[i]->bytes_in_buffer = 0;
             data->streams[i]->buffer_full = 0;
             data->streams[i]->buffer_used = 0;
+            data->streams[i]->samples_filled = 0;
+            data->streams[i]->samples_used = 0;
+            data->streams[i]->current_size_count = 0;
+            data->streams[i]->current_size_target = 0;
+            data->streams[i]->decode_to_discard = 0;
 
             /* force first offset as discard-looping needs to start from the beginning */
             if (vgmstream->loop_ch)
@@ -562,33 +571,36 @@ void seek_mpeg(VGMSTREAM *vgmstream, int32_t num_sample) {
         data->samples_to_discard += data->skip_samples;
     }
 
+    data->bytes_in_buffer = 0;
     data->buffer_full = 0;
     data->buffer_used = 0;
 }
 
-/* resets mpg123 decoder and its internals (with mpg123_open_feed as mpg123_feedseek won't work) */
+/* resets mpg123 decoder and its internals without seeking, useful when a new MPEG substream starts */
 void flush_mpeg(mpeg_codec_data * data) {
     if (!data)
         return;
 
     if (!data->custom) {
         /* input_offset is ignored as we can assume it will be 0 for a seek to sample 0 */
-        mpg123_open_feed(data->m);
+        mpg123_open_feed(data->m); /* mpg123_feedseek won't work */
     }
     else {
         int i;
         /* re-start from 0 */
         for (i=0; i < data->streams_size; i++) {
             mpg123_open_feed(data->streams[i]->m);
-            data->streams[i]->samples_filled = 0;
-            data->streams[i]->samples_used = 0;
-            data->streams[i]->decode_to_discard = 0;
             data->streams[i]->bytes_in_buffer = 0;
             data->streams[i]->buffer_full = 0;
             data->streams[i]->buffer_used = 0;
+            data->streams[i]->samples_filled = 0;
+            data->streams[i]->samples_used = 0;
+            data->streams[i]->current_size_count = 0;
+            data->streams[i]->current_size_target = 0;
+            data->streams[i]->decode_to_discard = 0;
         }
 
-        data->samples_to_discard = data->skip_samples; /* initial delay */
+        data->samples_to_discard = data->skip_samples;
     }
 
     data->bytes_in_buffer = 0;