From 282d2fa445ff68771fe1c89769e9d66eb3f505e3 Mon Sep 17 00:00:00 2001
From: Leon Styhre <leon@leonstyhre.com>
Date: Sat, 15 May 2021 20:16:48 +0200
Subject: [PATCH] Implemented a workaround for a potential crash when scaling
frames in VideoFFmpegComponent.
---
.../src/components/VideoFFmpegComponent.cpp | 22 ++++++++++++++-----
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/es-core/src/components/VideoFFmpegComponent.cpp b/es-core/src/components/VideoFFmpegComponent.cpp
index c539d1f69..bffad8cfc 100644
--- a/es-core/src/components/VideoFFmpegComponent.cpp
+++ b/es-core/src/components/VideoFFmpegComponent.cpp
@@ -221,7 +221,7 @@ void VideoFFmpegComponent::readFrames()
// We have a video frame that needs conversion to RGBA format.
uint8_t* frameRGBA[4];
- int lineSizes[4];
+ int lineSize[4];
int allocatedSize = 0;
// The pts value is the presentation time, i.e. the time stamp when
@@ -231,10 +231,20 @@ void VideoFFmpegComponent::readFrames()
double pts = static_cast<double>(mPacket->dts) *
av_q2d(mVideoStream->time_base);
+ // Due to some unknown reason, attempting to scale frames where
+ // coded_width is larger than width leads to graphics corruption or
+ // crashes. The only workaround I've been able to find is to decrease the
+ // source width by one pixel. Unfortunately this leads to a noticeably
+ // softer picture, but as few videos have this issue it's an acceptable
+ // workaround for now. Possibly this problem is caused by an FFmpeg bug.
+ int sourceWidth = mVideoCodecContext->width;
+ if (mVideoCodecContext->coded_width > mVideoCodecContext->width)
+ sourceWidth--;
+
// Conversion using libswscale.
struct SwsContext* conversionContext = sws_getContext(
- mVideoCodecContext->coded_width,
- mVideoCodecContext->coded_height,
+ sourceWidth,
+ mVideoCodecContext->height,
mVideoCodecContext->pix_fmt,
mVideoFrame->width,
mVideoFrame->height,
@@ -246,7 +256,7 @@ void VideoFFmpegComponent::readFrames()
allocatedSize = av_image_alloc(
frameRGBA,
- lineSizes,
+ lineSize,
mVideoFrame->width,
mVideoFrame->height,
AV_PIX_FMT_RGB32,
@@ -257,9 +267,9 @@ void VideoFFmpegComponent::readFrames()
const_cast<uint8_t const* const*>(mVideoFrame->data),
mVideoFrame->linesize,
0,
- mVideoCodecContext->coded_height,
+ mVideoCodecContext->height,
frameRGBA,
- lineSizes);
+ lineSize);
VideoFrame currFrame;