From e0175ac494ac0d4565c75a0e2676ccf4831e69a2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89lo=C3=AFse=20Brosseau?= <eloise.brosseau@autodesk.com>
Date: Wed, 13 Nov 2024 14:40:34 -0500
Subject: [PATCH] Enable first frame to start at 0
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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Signed-off-by: Éloïse Brosseau <eloise.brosseau@autodesk.com>
---
 src/lib/image/MovieFFMpeg/MovieFFMpeg.cpp |  5 ++---
 src/lib/ip/IPBaseNodes/StackIPNode.cpp    |  2 +-
 src/lib/ip/IPCore/Session.cpp             | 24 +++++++++++------------
 3 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/src/lib/image/MovieFFMpeg/MovieFFMpeg.cpp b/src/lib/image/MovieFFMpeg/MovieFFMpeg.cpp
index 45267f488..4f4156fb2 100644
--- a/src/lib/image/MovieFFMpeg/MovieFFMpeg.cpp
+++ b/src/lib/image/MovieFFMpeg/MovieFFMpeg.cpp
@@ -1331,9 +1331,8 @@ MovieFFMpegReader::getFirstFrame(AVRational rate)
     // offset by the given positive value.
     //
 
-    m_formatStartFrame = max(int64_t(0), int64_t(0.49 + av_q2d(rate) *
-        double(m_avFormatContext->start_time) / double(AV_TIME_BASE)));
-    int64_t firstFrame = max(int64_t(m_formatStartFrame), int64_t(1));
+    int64_t firstFrame = std::max(static_cast<int64_t>(0), static_cast<int64_t>(0.49 + av_q2d(rate) *
+        static_cast<double>(m_avFormatContext->start_time) / static_cast<double>(AV_TIME_BASE)));
 
     for (int i = 0; i < m_avFormatContext->nb_streams; i++)
     {
diff --git a/src/lib/ip/IPBaseNodes/StackIPNode.cpp b/src/lib/ip/IPBaseNodes/StackIPNode.cpp
index 293f813bb..965f37474 100644
--- a/src/lib/ip/IPBaseNodes/StackIPNode.cpp
+++ b/src/lib/ip/IPBaseNodes/StackIPNode.cpp
@@ -291,7 +291,7 @@ StackIPNode::computeRanges()
 
     m_info.cutIn  = m_info.start;
     m_info.cutOut = m_info.end;
-    m_offset      = m_info.start - 1;
+    m_offset      = std::max(m_info.start - 1, 0);
 
     if (m_outputFPS->front() == 0.0 && !m_rangeInfos.empty() && ! m_rangeInfos[0].isUndiscovered)
     {
diff --git a/src/lib/ip/IPCore/Session.cpp b/src/lib/ip/IPCore/Session.cpp
index 71b455bb0..1508370fd 100644
--- a/src/lib/ip/IPCore/Session.cpp
+++ b/src/lib/ip/IPCore/Session.cpp
@@ -312,14 +312,14 @@ Session::Session(IPGraph* graph)
       m_waitForUploadThreadPrefetch(false),
       m_readingGTO(false),
       m_sessionType(SequenceSession),
-      m_rangeStart(1),
-      m_rangeEnd(2),
+      m_rangeStart(0),
+      m_rangeEnd(1),
       m_outputVideoDevice(0),
       m_controlVideoDevice(0),
-      m_narrowedRangeStart(1),
-      m_narrowedRangeEnd(2),
-      m_inPoint(1),
-      m_outPoint(2),
+      m_narrowedRangeStart(0),
+      m_narrowedRangeEnd(1),
+      m_inPoint(0),
+      m_outPoint(1),
       m_notPersistent(0),
       m_inc(1),
       //m_loadingError(false),
@@ -336,7 +336,7 @@ Session::Session(IPGraph* graph)
       m_overhead(0),
       m_shift(0),
       m_skipped(0),
-      m_frame(1),
+      m_frame(0),
       m_fastStart(true),
       m_bufferWait(false),
       m_latencyWait(false),
@@ -1706,11 +1706,11 @@ Session::clear()
     graph().flushAudioCache();
     if (!m_beingDeleted) graph().reset(App()->videoModules());
     setFileName("Untitled");
-    setInPoint(1);
-    setOutPoint(2);
-    setRangeStart(1);
-    setRangeEnd(2);
-    setFrameInternal(1);
+    setInPoint(0);
+    setOutPoint(1);
+    setRangeStart(0);
+    setRangeEnd(1);
+    setFrameInternal(0);
 
     if (!m_beingDeleted)
     {