added keyframe for speed increase when decoding hopefully

util/output/video.hpp

@@ -1,6 +1,7 @@
 #ifndef VIDEO_HPP
 #define VIDEO_HPP
 
+
 #include "frame.hpp"
 #include <vector>
 #include <cstdint>
@@ -8,16 +9,19 @@
 #include <memory>
 #include <algorithm>
 #include <iostream>
+#include <unordered_map>
 #include "../timing_decorator.hpp"
 
 class video {
 private:
     std::vector<std::vector<std::pair<uint8_t, uint32_t>>> compressed_frames_;
+    std::unordered_map<size_t, size_t> keyframe_indices_; // Maps frame index to keyframe index
     size_t width_;
     size_t height_;
     std::vector<char> channels_;
     double fps_;
     bool use_differential_encoding_;
+    size_t keyframe_interval_;
 
     // Compress frame using differential encoding
     std::vector<std::pair<uint8_t, uint32_t>> compress_with_differential(
@@ -25,7 +29,7 @@ private:
         TIME_FUNCTION;
         
         if (previous_frame == nullptr) {
-            // First frame - compress normally
+            // First frame or keyframe - compress normally
             return current_frame.compress_rle();
         }
         
@@ -69,15 +73,78 @@ private:
         return frame(reconstructed_data, width_, height_, channels_);
     }
 
+    // Find the nearest keyframe index for a given frame index
+    size_t find_nearest_keyframe(size_t frame_index) const {
+        if (keyframe_indices_.empty()) return 0;
+        
+        // Keyframes are stored at intervals, so we can calculate the nearest one
+        size_t keyframe_idx = (frame_index / keyframe_interval_) * keyframe_interval_;
+        
+        // Make sure the keyframe exists
+        if (keyframe_idx >= compressed_frames_.size()) {
+            // Find the last available keyframe
+            for (size_t i = frame_index; i > 0; --i) {
+                if (keyframe_indices_.count(i)) {
+                    return i;
+                }
+            }
+            return 0;
+        }
+        
+        return keyframe_idx;
+    }
+
+    // Build keyframe indices (call this when frames change)
+    void rebuild_keyframe_indices() {
+        keyframe_indices_.clear();
+        for (size_t i = 0; i < compressed_frames_.size(); i += keyframe_interval_) {
+            if (i < compressed_frames_.size()) {
+                keyframe_indices_[i] = i;
+            }
+        }
+        // Always ensure frame 0 is a keyframe
+        if (!compressed_frames_.empty() && !keyframe_indices_.count(0)) {
+            keyframe_indices_[0] = 0;
+        }
+    }
+
+    // Get frame with keyframe optimization - much faster for random access
+    frame get_frame_optimized(size_t index) const {
+        if (index >= compressed_frames_.size()) {
+            throw std::out_of_range("Frame index out of range");
+        }
+        
+        // If it's a keyframe or we're not using differential encoding, decompress directly
+        if (keyframe_indices_.count(index) || !use_differential_encoding_) {
+            frame result;
+            result.decompress_rle(compressed_frames_[index]);
+            result.resize(width_, height_, channels_);
+            return result;
+        }
+        
+        // Find the nearest keyframe
+        size_t keyframe_idx = find_nearest_keyframe(index);
+        
+        // Decompress the keyframe first
+        frame current_frame = get_frame_optimized(keyframe_idx);
+        
+        // Then decompress all frames from keyframe to target frame
+        for (size_t i = keyframe_idx + 1; i <= index; ++i) {
+            current_frame = decompress_differential(compressed_frames_[i], current_frame);
+        }
+        
+        return current_frame;
+    }
+
 public:
     // Default constructor
-    video() : width_(0), height_(0), fps_(30.0), use_differential_encoding_(true) {}
+    video() : width_(0), height_(0), fps_(30.0), use_differential_encoding_(true), keyframe_interval_(50) {}
     
     // Constructor with dimensions and settings
     video(size_t width, size_t height, const std::vector<char>& channels = {'\0'},
-          double fps = 30.0, bool use_differential = true)
+          double fps = 30.0, bool use_differential = true, size_t keyframe_interval = 50)
         : width_(width), height_(height), channels_(channels), fps_(fps),
-          use_differential_encoding_(use_differential) {
+          use_differential_encoding_(use_differential), keyframe_interval_(keyframe_interval) {
         
         if (width == 0 || height == 0) {
             throw std::invalid_argument("Dimensions must be positive");
@@ -88,12 +155,15 @@ public:
         if (fps <= 0) {
             throw std::invalid_argument("FPS must be positive");
         }
+        if (keyframe_interval == 0) {
+            throw std::invalid_argument("Keyframe interval must be positive");
+        }
     }
     
     // Constructor with initializer list for channels
     video(size_t width, size_t height, std::initializer_list<char> channels,
-          double fps = 30.0, bool use_differential = true)
+          double fps = 30.0, bool use_differential = true, size_t keyframe_interval = 50)
-        : video(width, height, std::vector<char>(channels), fps, use_differential) {}
+        : video(width, height, std::vector<char>(channels), fps, use_differential, keyframe_interval) {}
     
     // Accessors
     size_t width() const noexcept { return width_; }
@@ -103,6 +173,8 @@ public:
     bool use_differential_encoding() const noexcept { return use_differential_encoding_; }
     size_t frame_count() const noexcept { return compressed_frames_.size(); }
     size_t channels_count() const noexcept { return channels_.size(); }
+    size_t keyframe_interval() const noexcept { return keyframe_interval_; }
+    const std::unordered_map<size_t, size_t>& keyframe_indices() const noexcept { return keyframe_indices_; }
     
     // Check if video is empty
     bool empty() const noexcept {
@@ -120,43 +192,61 @@ public:
             throw std::invalid_argument("Frame channels must match video channels");
         }
         
+        size_t new_index = compressed_frames_.size();
+        
         if (compressed_frames_.empty() || !use_differential_encoding_) {
             // First frame or differential encoding disabled - compress normally
             compressed_frames_.push_back(new_frame.compress_rle());
         } else {
-            // Get the previous frame for differential encoding
+            // Check if this should be a keyframe
-            frame prev_frame = get_frame(frame_count() - 1);
+            bool is_keyframe = (new_index % keyframe_interval_ == 0);
+            
+            if (is_keyframe) {
+                // Keyframe - compress normally
+                compressed_frames_.push_back(new_frame.compress_rle());
+                keyframe_indices_[new_index] = new_index;
+            } else {
+                // Regular frame - use differential encoding from previous frame
+                frame prev_frame = get_frame_optimized(new_index - 1);
                 compressed_frames_.push_back(compress_with_differential(new_frame, &prev_frame));
             }
         }
         
+        // Ensure we have keyframe at index 0
+        if (compressed_frames_.size() == 1) {
+            keyframe_indices_[0] = 0;
+        }
+    }
+    
     // Add frame with move semantics
     void add_frame(frame&& new_frame) {
         add_frame(new_frame); // Just call the const version
     }
     
-    // Get a specific frame
+    // Get a specific frame (uses optimized version with keyframes)
     frame get_frame(size_t index) const {
+        TIME_FUNCTION;
+        if (!use_differential_encoding_ || keyframe_indices_.empty()) {
+            // Fallback to original method if no optimization possible
             if (index >= compressed_frames_.size()) {
                 throw std::out_of_range("Frame index out of range");
             }
             
             if (index == 0 || !use_differential_encoding_) {
-            // First frame or no differential encoding - decompress normally
                 frame result;
                 result.decompress_rle(compressed_frames_[index]);
-            
-            // Set dimensions and channels
                 result.resize(width_, height_, channels_);
                 return result;
             } else {
-            // Differential encoded frame - need previous frame to reconstruct
                 frame prev_frame = get_frame(index - 1);
                 return decompress_differential(compressed_frames_[index], prev_frame);
             }
         }
         
-    // Get multiple frames as a sequence
+        return get_frame_optimized(index);
+    }
+    
+    // Get multiple frames as a sequence (optimized for sequential access)
     std::vector<frame> get_frames(size_t start_index, size_t count) const {
         TIME_FUNCTION;
         if (start_index >= compressed_frames_.size()) {
@@ -167,9 +257,39 @@ public:
         std::vector<frame> frames;
         frames.reserve(count);
         
+        if (!use_differential_encoding_ || keyframe_indices_.empty()) {
+            // Original sequential method
             for (size_t i = start_index; i < start_index + count; ++i) {
                 frames.push_back(get_frame(i));
             }
+        } else {
+            // Optimized method: start from nearest keyframe
+            size_t current_index = start_index;
+            size_t keyframe_idx = find_nearest_keyframe(start_index);
+            
+            // Get the keyframe
+            frame current_frame = get_frame_optimized(keyframe_idx);
+            
+            // If we started before the keyframe (shouldn't happen), handle it
+            if (keyframe_idx > start_index) {
+                // This is a fallback - should not normally occur
+                current_frame = get_frame_optimized(start_index);
+                current_index = start_index + 1;
+            } else if (keyframe_idx < start_index) {
+                // Decode frames from keyframe to start_index
+                for (size_t i = keyframe_idx + 1; i < start_index; ++i) {
+                    current_frame = decompress_differential(compressed_frames_[i], current_frame);
+                }
+            }
+            
+            // Now add the requested frames
+            for (size_t i = start_index; i < start_index + count; ++i) {
+                if (i > keyframe_idx) {
+                    current_frame = decompress_differential(compressed_frames_[i], current_frame);
+                }
+                frames.push_back(current_frame);
+            }
+        }
         
         return frames;
     }
@@ -185,11 +305,13 @@ public:
             throw std::out_of_range("Frame index out of range");
         }
         compressed_frames_.erase(compressed_frames_.begin() + index);
+        rebuild_keyframe_indices();
     }
     
     // Clear all frames
     void clear_frames() noexcept {
         compressed_frames_.clear();
+        keyframe_indices_.clear();
     }
     
     // Replace a frame
@@ -207,19 +329,37 @@ public:
             throw std::invalid_argument("Frame channels must match video channels");
         }
         
-        if (index == 0 || !use_differential_encoding_) {
+        bool was_keyframe = keyframe_indices_.count(index);
+        bool should_be_keyframe = (index % keyframe_interval_ == 0);
+        
+        if (index == 0 || !use_differential_encoding_ || should_be_keyframe) {
+            // Keyframe or no differential encoding - compress normally
             compressed_frames_[index] = new_frame.compress_rle();
+            if (should_be_keyframe) {
+                keyframe_indices_[index] = index;
+            }
         } else {
-            frame prev_frame = get_frame(index - 1);
+            // Differential frame
+            frame prev_frame = get_frame_optimized(index - 1);
             compressed_frames_[index] = compress_with_differential(new_frame, &prev_frame);
+            
+            // Remove from keyframes if it was one but shouldn't be
+            if (was_keyframe && !should_be_keyframe) {
+                keyframe_indices_.erase(index);
+            }
         }
         
         // If this isn't the last frame, we need to update the next frame's differential encoding
         if (use_differential_encoding_ && index + 1 < compressed_frames_.size()) {
-            frame current_frame = get_frame(index);
+            frame current_frame = get_frame_optimized(index);
-            frame next_frame_original = get_frame(index + 1);
+            frame next_frame_original = get_frame_optimized(index + 1);
             compressed_frames_[index + 1] = compress_with_differential(next_frame_original, &current_frame);
         }
+        
+        // Rebuild keyframe indices if we changed keyframe status
+        if (was_keyframe != should_be_keyframe) {
+            rebuild_keyframe_indices();
+        }
     }
     
     // Set FPS
@@ -251,6 +391,45 @@ public:
         }
     }
     
+    // Set keyframe interval and rebuild indices
+    void set_keyframe_interval(size_t interval) {
+        if (interval == 0) {
+            throw std::invalid_argument("Keyframe interval must be positive");
+        }
+        
+        if (interval != keyframe_interval_) {
+            keyframe_interval_ = interval;
+            if (!compressed_frames_.empty()) {
+                // Rebuild keyframe indices with new interval
+                rebuild_keyframe_indices();
+                
+                // If we have frames, we may need to recompress some as keyframes
+                if (use_differential_encoding_) {
+                    auto original_frames = get_all_frames();
+                    clear_frames();
+                    
+                    for (const auto& f : original_frames) {
+                        add_frame(f);
+                    }
+                }
+            }
+        }
+    }
+    
+    // Force a specific frame to be a keyframe
+    void make_keyframe(size_t index) {
+        if (index >= compressed_frames_.size()) {
+            throw std::out_of_range("Frame index out of range");
+        }
+        
+        if (!keyframe_indices_.count(index)) {
+            // Recompress this frame as a keyframe
+            frame original_frame = get_frame_optimized(index);
+            compressed_frames_[index] = original_frame.compress_rle();
+            keyframe_indices_[index] = index;
+        }
+    }
+    
     // Get video duration in seconds
     double duration() const noexcept {
         TIME_FUNCTION;
@@ -310,6 +489,8 @@ public:
         double overall_ratio;
         double average_frame_ratio;
         double video_duration;
+        size_t keyframe_count;
+        size_t keyframe_interval;
     };
     
     compression_stats get_compression_stats() const {
@@ -321,6 +502,8 @@ public:
         stats.overall_ratio = overall_compression_ratio();
         stats.average_frame_ratio = average_frame_compression_ratio();
         stats.video_duration = duration();
+        stats.keyframe_count = keyframe_indices_.size();
+        stats.keyframe_interval = keyframe_interval_;
         return stats;
     }
     
@@ -332,10 +515,11 @@ public:
         }
         
         frame_count = std::min(frame_count, compressed_frames_.size() - start_frame);
-        video result(width_, height_, channels_, fps_, use_differential_encoding_);
+        video result(width_, height_, channels_, fps_, use_differential_encoding_, keyframe_interval_);
         
+        // Add frames one by one to maintain proper keyframe structure
         for (size_t i = start_frame; i < start_frame + frame_count; ++i) {
-            result.compressed_frames_.push_back(compressed_frames_[i]);
+            result.add_frame(get_frame(i));
         }
         
         return result;
@@ -348,30 +532,23 @@ public:
             throw std::invalid_argument("Videos must have same dimensions and channels");
         }
         
-        // If both use differential encoding, we can directly append compressed frames
+        // Add frames one by one to maintain proper keyframe structure
-        if (use_differential_encoding_ && other.use_differential_encoding_) {
-            compressed_frames_.insert(compressed_frames_.end(),
-                                    other.compressed_frames_.begin(),
-                                    other.compressed_frames_.end());
-        } else {
-            // Otherwise, we need to decompress and recompress
         auto other_frames = other.get_all_frames();
         for (const auto& frame : other_frames) {
             add_frame(frame);
         }
     }
-    }
     
-    // Save/Load functionality (basic serialization)
+    // Save/Load functionality (basic serialization) - updated for keyframes
     std::vector<uint8_t> serialize() const {
         TIME_FUNCTION;
         // Simple serialization format:
         // [header][compressed_frame_data...]
-        // Header: width(4), height(4), channels_count(1), channels_data(n), fps(8), frame_count(4)
+        // Header: width(4), height(4), channels_count(1), channels_data(n), fps(8), 
+        //         use_diff(1), keyframe_interval(4), frame_count(4), keyframe_count(4), keyframe_indices...
         
         std::vector<uint8_t> result;
         
-        // Header
         auto add_uint32 = [&result](uint32_t value) {
             for (int i = 0; i < 4; ++i) {
                 result.push_back((value >> (i * 8)) & 0xFF);
@@ -394,8 +571,15 @@ public:
         }
         add_double(fps_);
         result.push_back(use_differential_encoding_ ? 1 : 0);
+        add_uint32(static_cast<uint32_t>(keyframe_interval_));
         add_uint32(static_cast<uint32_t>(compressed_frames_.size()));
         
+        // Write keyframe indices
+        add_uint32(static_cast<uint32_t>(keyframe_indices_.size()));
+        for (const auto& kv : keyframe_indices_) {
+            add_uint32(static_cast<uint32_t>(kv.first));
+        }
+        
         // Write compressed frames
         for (const auto& compressed_frame : compressed_frames_) {
             add_uint32(static_cast<uint32_t>(compressed_frame.size()));
@@ -411,7 +595,7 @@ public:
     // Deserialize from byte data
     static video deserialize(const std::vector<uint8_t>& data) {
         TIME_FUNCTION;
-        if (data.size() < 4 + 4 + 1 + 8 + 1 + 4) { // Minimum header size
+        if (data.size() < 4 + 4 + 1 + 8 + 1 + 4 + 4 + 4) { // Minimum header size
             throw std::invalid_argument("Invalid video data: too short");
         }
         
@@ -448,9 +632,17 @@ public:
         
         double fps = read_double();
         bool use_diff = data[pos++] != 0;
+        uint32_t keyframe_interval = read_uint32();
         uint32_t frame_count = read_uint32();
         
-        video result(width, height, channels, fps, use_diff);
+        video result(width, height, channels, fps, use_diff, keyframe_interval);
+        
+        // Read keyframe indices
+        uint32_t keyframe_count = read_uint32();
+        for (uint32_t i = 0; i < keyframe_count; ++i) {
+            uint32_t keyframe_index = read_uint32();
+            result.keyframe_indices_[keyframe_index] = keyframe_index;
+        }
         
         // Read compressed frames
         for (uint32_t i = 0; i < frame_count; ++i) {