From 0faa3286aad09cb8aa5737c0f9d4f4e5ba8edc63 Mon Sep 17 00:00:00 2001
From: bnnm <bananaman255@gmail.com>
Date: Sat, 3 Dec 2016 11:42:38 +0100
Subject: [PATCH] Don't manually check framesRead and rely on FFmpeg's EOFs

FFmpeg's duration isn't always reliable (ie. bad headers) and the
decoder detects EOFs already, extra decoding attempts should be ignored.
This way vgmstream can use other values without modifying
ffmpeg_codec_data's state.
---
 src/coding/ffmpeg_decoder.c | 16 +++-------------
 src/meta/ffmpeg.c           |  1 -
 src/vgmstream.h             |  1 -
 3 files changed, 3 insertions(+), 15 deletions(-)

diff --git a/src/coding/ffmpeg_decoder.c b/src/coding/ffmpeg_decoder.c
index 33af01c7..345be981 100644
--- a/src/coding/ffmpeg_decoder.c
+++ b/src/coding/ffmpeg_decoder.c
@@ -59,8 +59,7 @@ static void convert_audio(sample *outbuf, const uint8_t *inbuf, int sampleCount,
     }
 }
 
-void decode_ffmpeg(VGMSTREAM *vgmstream,
-        sample * outbuf, int32_t samples_to_do, int channels) {
+void decode_ffmpeg(VGMSTREAM *vgmstream, sample * outbuf, int32_t samples_to_do, int channels) {
     ffmpeg_codec_data *data = (ffmpeg_codec_data *) vgmstream->codec_data;
     
     int bytesPerSample;
@@ -87,7 +86,7 @@ void decode_ffmpeg(VGMSTREAM *vgmstream,
     
 
     /* ignore decode attempts at EOF */
-    if ((data->totalFrames && data->framesRead >= data->totalFrames) || data->endOfStream || data->endOfAudio) {
+    if (data->endOfStream || data->endOfAudio) {
         memset(outbuf, 0, samples_to_do * channels * sizeof(sample));
         return;
     }
@@ -231,11 +230,6 @@ void decode_ffmpeg(VGMSTREAM *vgmstream,
     
 end:
     framesReadNow = bytesRead / frameSize;
-    if (data->totalFrames && (data->framesRead + framesReadNow > data->totalFrames)) {
-        framesReadNow = (int)(data->totalFrames - data->framesRead);
-    }
-    
-    data->framesRead += framesReadNow;
     
     // Convert the audio
     convert_audio(outbuf, data->sampleBuffer, framesReadNow * channels, data->bitsPerSample, data->floatingPoint);
@@ -259,7 +253,6 @@ void reset_ffmpeg(VGMSTREAM *vgmstream) {
     }
     data->readNextPacket = 1;
     data->bytesConsumedFromDecodedFrame = INT_MAX;
-    data->framesRead = 0;
     data->endOfStream = 0;
     data->endOfAudio = 0;
     data->samplesToDiscard = 0;
@@ -286,11 +279,9 @@ void seek_ffmpeg(VGMSTREAM *vgmstream, int32_t num_sample) {
 
     /* todo fix this properly */
     if (data->totalFrames) {
-        data->framesRead = (int)ts;
-        ts = data->framesRead * (data->formatCtx->duration) / data->totalFrames;
+        ts = (int)ts * (data->formatCtx->duration) / data->totalFrames;
     } else {
         data->samplesToDiscard = num_sample;
-        data->framesRead = 0;
         ts = 0;
     }
 
@@ -303,7 +294,6 @@ void seek_ffmpeg(VGMSTREAM *vgmstream, int32_t num_sample) {
     /* We could also seek by offset (AVSEEK_FLAG_BYTE) to the frame closest to the loop then discard
      *  some samples, which is fast but would need calculations per format / when frame size is not constant */
     data->samplesToDiscard = num_sample;
-    data->framesRead = 0;
     ts = 0;
 
     avformat_seek_file(data->formatCtx, data->streamIndex, ts, ts, ts, AVSEEK_FLAG_ANY);
diff --git a/src/meta/ffmpeg.c b/src/meta/ffmpeg.c
index 45b38bfa..e77c0c60 100644
--- a/src/meta/ffmpeg.c
+++ b/src/meta/ffmpeg.c
@@ -332,7 +332,6 @@ ffmpeg_codec_data * init_ffmpeg_faux_riff(STREAMFILE *streamFile, int64_t fmt_of
     }
 
     data->bitrate = (int)(data->codecCtx->bit_rate);
-    data->framesRead = 0;
     data->endOfStream = 0;
     data->endOfAudio = 0;
 
diff --git a/src/vgmstream.h b/src/vgmstream.h
index 1a71487a..483105fd 100644
--- a/src/vgmstream.h
+++ b/src/vgmstream.h
@@ -870,7 +870,6 @@ typedef struct {
     int floatingPoint;
     int sampleRate;
     int64_t totalFrames; // sample count, or 0 if unknown
-    int64_t framesRead;
     int bitrate;
     
     // Intermediate buffer