From 4f3e4919f51c8a6d2808e5a0b4d0c1139f5e11c9 Mon Sep 17 00:00:00 2001
From: Nicolas Hug <contact@nicolas-hug.com>
Date: Tue, 21 Jan 2025 17:01:15 +0000
Subject: [PATCH] Better variable names for `scanFileAndUpdateMetadataAndIndex`
 (#454)

---
 .../decoders/_core/VideoDecoder.cpp           | 40 ++++++++++---------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/src/torchcodec/decoders/_core/VideoDecoder.cpp b/src/torchcodec/decoders/_core/VideoDecoder.cpp
index 520977a9..6a74f51d 100644
--- a/src/torchcodec/decoders/_core/VideoDecoder.cpp
+++ b/src/torchcodec/decoders/_core/VideoDecoder.cpp
@@ -562,13 +562,14 @@ void VideoDecoder::scanFileAndUpdateMetadataAndIndex() {
     if (packet->flags & AV_PKT_FLAG_DISCARD) {
       continue;
     }
-    auto& stream = containerMetadata_.streams[streamIndex];
-    stream.minPtsFromScan =
-        std::min(stream.minPtsFromScan.value_or(INT64_MAX), packet->pts);
-    stream.maxPtsFromScan = std::max(
-        stream.maxPtsFromScan.value_or(INT64_MIN),
+    auto& streamMetadata = containerMetadata_.streams[streamIndex];
+    streamMetadata.minPtsFromScan = std::min(
+        streamMetadata.minPtsFromScan.value_or(INT64_MAX), packet->pts);
+    streamMetadata.maxPtsFromScan = std::max(
+        streamMetadata.maxPtsFromScan.value_or(INT64_MIN),
         packet->pts + packet->duration);
-    stream.numFramesFromScan = stream.numFramesFromScan.value_or(0) + 1;
+    streamMetadata.numFramesFromScan =
+        streamMetadata.numFramesFromScan.value_or(0) + 1;
 
     FrameInfo frameInfo;
     frameInfo.pts = packet->pts;
@@ -578,16 +579,17 @@ void VideoDecoder::scanFileAndUpdateMetadataAndIndex() {
     }
     streams_[streamIndex].allFrames.push_back(frameInfo);
   }
-  for (size_t i = 0; i < containerMetadata_.streams.size(); ++i) {
-    auto& streamMetadata = containerMetadata_.streams[i];
-    auto stream = formatContext_->streams[i];
+  for (size_t streamIndex = 0; streamIndex < containerMetadata_.streams.size();
+       ++streamIndex) {
+    auto& streamMetadata = containerMetadata_.streams[streamIndex];
+    auto avStream = formatContext_->streams[streamIndex];
     if (streamMetadata.minPtsFromScan.has_value()) {
       streamMetadata.minPtsSecondsFromScan =
-          *streamMetadata.minPtsFromScan * av_q2d(stream->time_base);
+          *streamMetadata.minPtsFromScan * av_q2d(avStream->time_base);
     }
     if (streamMetadata.maxPtsFromScan.has_value()) {
       streamMetadata.maxPtsSecondsFromScan =
-          *streamMetadata.maxPtsFromScan * av_q2d(stream->time_base);
+          *streamMetadata.maxPtsFromScan * av_q2d(avStream->time_base);
     }
   }
   int ffmepgStatus =
@@ -597,23 +599,23 @@ void VideoDecoder::scanFileAndUpdateMetadataAndIndex() {
         "Could not seek file to pts=0: " +
         getFFMPEGErrorStringFromErrorCode(ffmepgStatus));
   }
-  for (auto& [streamIndex, stream] : streams_) {
+  for (auto& [streamIndex, streamInfo] : streams_) {
     std::sort(
-        stream.keyFrames.begin(),
-        stream.keyFrames.end(),
+        streamInfo.keyFrames.begin(),
+        streamInfo.keyFrames.end(),
         [](const FrameInfo& frameInfo1, const FrameInfo& frameInfo2) {
           return frameInfo1.pts < frameInfo2.pts;
         });
     std::sort(
-        stream.allFrames.begin(),
-        stream.allFrames.end(),
+        streamInfo.allFrames.begin(),
+        streamInfo.allFrames.end(),
         [](const FrameInfo& frameInfo1, const FrameInfo& frameInfo2) {
           return frameInfo1.pts < frameInfo2.pts;
         });
 
-    for (size_t i = 0; i < stream.allFrames.size(); ++i) {
-      if (i + 1 < stream.allFrames.size()) {
-        stream.allFrames[i].nextPts = stream.allFrames[i + 1].pts;
+    for (size_t i = 0; i < streamInfo.allFrames.size(); ++i) {
+      if (i + 1 < streamInfo.allFrames.size()) {
+        streamInfo.allFrames[i].nextPts = streamInfo.allFrames[i + 1].pts;
       }
     }
   }