From 7f219aa369068a5d872435ddc7741a5d3ab966c6 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Tue, 9 May 2023 10:57:23 -0400
Subject: [PATCH] audio: Make sure AudioStream's internal buffers are large
enough.
It needs to deal with ConvertAudio growing buffers in-place, as it might
convert smaller types to float as an intermediate step.
---
src/audio/SDL_audiocvt.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/src/audio/SDL_audiocvt.c b/src/audio/SDL_audiocvt.c
index 035c074628c0..47879c10abaa 100644
--- a/src/audio/SDL_audiocvt.c
+++ b/src/audio/SDL_audiocvt.c
@@ -475,6 +475,17 @@ static int GetMemsetSilenceValue(const SDL_AudioFormat fmt)
return (fmt == SDL_AUDIO_U8) ? 0x80 : 0x00;
}
+/* figure out the largest thing we might need for ConvertAudio, which might grow data in-place. */
+static int CalculateMaxSampleFrameSize(SDL_AudioFormat src_format, int src_channels, SDL_AudioFormat dst_format, int dst_channels)
+{
+ const int src_format_size = SDL_AUDIO_BITSIZE(src_format) / 8;
+ const int dst_format_size = SDL_AUDIO_BITSIZE(dst_format) / 8;
+ const int max_app_format_size = SDL_max(src_format_size, dst_format_size);
+ const int max_format_size = SDL_max(max_app_format_size, sizeof (float)); /* ConvertAudio converts to float internally. */
+ const int max_channels = SDL_max(src_channels, dst_channels);
+ return max_format_size * max_channels;
+}
+
/* this assumes you're holding the stream's lock (or are still creating the stream). */
static int SetAudioStreamFormat(SDL_AudioStream *stream, SDL_AudioFormat src_format, int src_channels, int src_rate, SDL_AudioFormat dst_format, int dst_channels, int dst_rate)
{
@@ -485,13 +496,14 @@ static int SetAudioStreamFormat(SDL_AudioStream *stream, SDL_AudioFormat src_for
This is decided in pre_resample_channels. */
const int src_sample_frame_size = (SDL_AUDIO_BITSIZE(src_format) / 8) * src_channels;
const int dst_sample_frame_size = (SDL_AUDIO_BITSIZE(dst_format) / 8) * dst_channels;
+ const int max_sample_frame_size = CalculateMaxSampleFrameSize(src_format, src_channels, dst_format, dst_channels);
const int prev_history_buffer_frames = stream->history_buffer_frames;
const int pre_resample_channels = SDL_min(src_channels, dst_channels);
const int resampler_padding_frames = GetResamplerPaddingFrames(src_rate, dst_rate);
- const size_t resampler_padding_allocation = ((size_t) resampler_padding_frames) * pre_resample_channels * sizeof (float);
- const size_t future_buffer_allocation = resampler_padding_frames * src_sample_frame_size;
+ const size_t resampler_padding_allocation = ((size_t) resampler_padding_frames) * max_sample_frame_size;
+ const size_t future_buffer_allocation = resampler_padding_allocation;
const int history_buffer_frames = GetHistoryBufferSampleFrames(resampler_padding_frames);
- const size_t history_buffer_allocation = history_buffer_frames * src_sample_frame_size;
+ const size_t history_buffer_allocation = history_buffer_frames * max_sample_frame_size;
Uint8 *history_buffer = stream->history_buffer;
Uint8 *future_buffer = stream->future_buffer;
float *padding;