From 99b5c26592269b0113deda644be1c74465c272f3 Mon Sep 17 00:00:00 2001
From: Thomas Goyne <plorkyeran@aegisub.org>
Date: Sun, 25 Nov 2012 07:45:54 -0800
Subject: [PATCH] Fix crash when playing audio before time 0
There were two checks for reads past the end rather than checks for
before start and after end.
Closes #1556.
---
aegisub/src/audio_provider.cpp | 73 +++++++++-----------
aegisub/src/include/aegisub/audio_provider.h | 2 +
2 files changed, 33 insertions(+), 42 deletions(-)
diff --git a/aegisub/src/audio_provider.cpp b/aegisub/src/audio_provider.cpp
index 1482a56d6..9fb06e715 100644
--- a/aegisub/src/audio_provider.cpp
+++ b/aegisub/src/audio_provider.cpp
@@ -80,56 +80,45 @@ void AudioProvider::GetAudioWithVolume(void *buf, int64_t start, int64_t count,
}
}
+void AudioProvider::ZeroFill(void *buf, int64_t count) const {
+ if (bytes_per_sample == 1)
+ // 8 bit formats are usually unsigned with bias 127
+ memset(buf, 127, count * channels);
+ else
+ // While everything else is signed
+ memset(buf, 0, count * bytes_per_sample * channels);
+}
+
void AudioProvider::GetAudio(void *buf, int64_t start, int64_t count) const {
- if (start+count > num_samples) {
- int64_t oldcount = count;
- count = num_samples-start;
- if (count < 0) count = 0;
-
- // Fill beyond with zero
- if (bytes_per_sample == 1) {
- char *temp = (char *) buf;
- for (int i=count;i<oldcount;i++) {
- temp[i] = 0;
- }
- }
- if (bytes_per_sample == 2) {
- short *temp = (short *) buf;
- for (int i=count;i<oldcount;i++) {
- temp[i] = 0;
- }
- }
+ if (start < 0) {
+ ZeroFill(buf, std::min(-start, count));
+ buf = static_cast<char *>(buf) + -start * bytes_per_sample * channels;
+ count += start;
+ start = 0;
}
if (start + count > num_samples) {
int64_t zero_count = std::min(count, start + count - num_samples);
count -= zero_count;
- char *zero_buf = static_cast<char *>(buf) + count * bytes_per_sample * channels;
-
- if (bytes_per_sample == 1)
- // 8 bit formats are usually unsigned with bias 127
- memset(zero_buf, 127, zero_count * channels);
- else
- // While everything else is signed
- memset(zero_buf, 0, zero_count * bytes_per_sample * channels);
+ ZeroFill(static_cast<char *>(buf) + count * bytes_per_sample * channels, zero_count);
}
- if (count > 0) {
- try {
- FillBuffer(buf, start, count);
- }
- catch (AudioDecodeError const& e) {
- LOG_E("audio_provider") << e.GetChainedMessage();
- memset(buf, 0, count*bytes_per_sample);
- return;
- }
- catch (...) {
- // FIXME: Poor error handling though better than none, to patch issue #800.
- // Just return blank audio if real provider fails.
- LOG_E("audio_provider") << "Unknown audio decoding error";
- memset(buf, 0, count*bytes_per_sample);
- return;
- }
+ if (count <= 0) return;
+
+ try {
+ FillBuffer(buf, start, count);
+ }
+ catch (AudioDecodeError const& e) {
+ LOG_E("audio_provider") << e.GetChainedMessage();
+ ZeroFill(buf, count);
+ return;
+ }
+ catch (...) {
+ // FIXME: Poor error handling though better than none, to patch issue #800.
+ // Just return blank audio if real provider fails.
+ LOG_E("audio_provider") << "Unknown audio decoding error";
+ ZeroFill(buf, count);
+ return;
}
}
diff --git a/aegisub/src/include/aegisub/audio_provider.h b/aegisub/src/include/aegisub/audio_provider.h
index fa7e67191..e029c6620 100644
--- a/aegisub/src/include/aegisub/audio_provider.h
+++ b/aegisub/src/include/aegisub/audio_provider.h
@@ -69,6 +69,8 @@ protected:
virtual void FillBuffer(void *buf, int64_t start, int64_t count) const = 0;
+ void ZeroFill(void *buf, int64_t count) const;
+
public:
virtual ~AudioProvider() { }
--
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