From d03d7187c1881237b1a98404a125507d33d85a0e Mon Sep 17 00:00:00 2001
From: Fox Caminiti <fox@foxcam.net>
Date: Sun, 21 Aug 2022 22:05:10 -0400
Subject: a bit of housekeeping

---
 ffmpeg_backend.cpp | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

(limited to 'ffmpeg_backend.cpp')

diff --git a/ffmpeg_backend.cpp b/ffmpeg_backend.cpp
index 03d3214..6e16e76 100644
--- a/ffmpeg_backend.cpp
+++ b/ffmpeg_backend.cpp
@@ -45,6 +45,9 @@ bool32 AV_TryFrame(av_info *AV, int32 *err)
     while (*err >= 0) {
         *err = avcodec_receive_frame(AV->VideoCodecContext, AV->VideoFrame);
         if (*err == AVERROR_EOF) {
+            av_seek_frame(AV->FileFormatContext, -1, 0, AVSEEK_FLAG_BACKWARD);
+            *err = 0;
+            break;
         } else if (*err == AVERROR(EAGAIN)) {
             *err = 0;
             break;
@@ -209,6 +212,11 @@ void AV_GetPTSAverage(source *Source, av_info *AV, int32 *err)
     // TODO(fox): This PTS average isn't exact and causes an occasional
     // frame skip. See libav remarks in forum for more details.
 
+    if (AV->VideoStream->duration == 1) {
+        Source->Info.AvgPTSPerFrame = 1;
+        return;
+    }
+
     // TODO(fox): Handle footage under five seconds.
     int16 TestAmount = 5;
 
@@ -234,6 +242,53 @@ void AV_GetPTSAverage(source *Source, av_info *AV, int32 *err)
     av_seek_frame(AV->FileFormatContext, -1, 0, AVSEEK_FLAG_BACKWARD);
 }
 
+cached_bitmap * AV_LoadStill(source *Source, layer_bitmap_info *BitmapInfo, memory *Memory)
+{
+    av_info *AV = (av_info *)BitmapInfo->AVInfo;
+    int32 *CurrentlyRenderedFrame = &BitmapInfo->CurrentFrame;
+
+    int32 err = 0;
+
+    *CurrentlyRenderedFrame = 0;
+
+    av_seek_frame(AV->FileFormatContext, -1, 0, AVSEEK_FLAG_FRAME);
+
+    while (err >= 0) {
+        if (AV_TryFrame(AV, &err))
+        {
+            uint16 Width = Source->Info.Width;
+            uint16 Height = Source->Info.Height;
+            uint16 BytesPerPixel = Source->Info.BytesPerPixel;
+            int32 Pitch = Width*BytesPerPixel;
+
+            cached_bitmap *Bitmap = Memory_RollingBitmap(Memory, Source, 0);
+            void *Buffer = Bitmap->Data;
+
+            int out_linesize[4] = { Pitch, Pitch, Pitch, Pitch };
+            uint8 *dst_data[4] = { (uint8 *)Buffer, (uint8 *)Buffer + Width*Height*BytesPerPixel,
+                                   (uint8 *)Buffer + Width*Height*BytesPerPixel*2, (uint8 *)Buffer + Width*Height*BytesPerPixel*3 };
+
+            // NOTE(fox): This function will be replaced in the future.
+            AV->RGBContext = sws_getContext(AV->VideoFrame->width, AV->VideoFrame->height, (AVPixelFormat)AV->VideoFrame->format,
+                                            AV->VideoFrame->width, AV->VideoFrame->height, AV_PIX_FMT_RGBA, SWS_BILINEAR,
+                                            NULL, NULL, NULL);
+
+            if(!AV->RGBContext) {
+                printf("Libav error: SwsContext creation failed.");
+            }
+
+            sws_scale(AV->RGBContext, AV->VideoFrame->data, AV->VideoFrame->linesize, 0, AV->VideoFrame->height,
+                      dst_data, out_linesize);
+
+            av_frame_unref(AV->VideoFrame);
+
+            Assert(BitmapInfo->BitmapBuffer);
+            return Bitmap;
+        }
+        av_frame_unref(AV->VideoFrame);
+    }
+    return 0;
+}
 
 cached_bitmap * AV_LoadVideoFrame(source *Source, layer_bitmap_info *BitmapInfo, memory *Memory, int32 TimelineFrame)
 {
-- 
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