TAV: decompression done on GPU

CLAUDE.md

@@ -120,6 +120,10 @@ Peripheral memories can be accessed using `vm.peek()` and `vm.poke()` functions,
 - JavaScript test programs available in `assets/disk0/`
 - Videotron2K assembly examples in documentation
 
+## Notes
+
+- The 'gzip' namespace in TSVM's JS programs is a misnomer: the actual 'gzip' functions (defined in CompressorDelegate.kt) call Zstd functions.
+
 ## TVDOS
 
 ### TVDOS Movie Formats

assets/disk0/tvdos/bin/playtav.js

@@ -69,18 +69,17 @@ let notifHideTimer = 0
 const NOTIF_SHOWUPTIME = 3000000000
 let [cy, cx] = con.getyx()
 
-let seqreadserial = require("seqread")
-let seqreadtape = require("seqreadtape")
+//let playgui = require("playgui")
 let seqread = undefined
 let fullFilePathStr = fullFilePath.full
 
 // Select seqread driver to use
-if (fullFilePathStr.startsWith('$:/TAPE') || fullFilePathStr.startsWith('$:\\\\TAPE')) {
-    seqread = seqreadtape
+if (fullFilePathStr.startsWith('$:/TAPE') || fullFilePathStr.startsWith('$:\\TAPE')) {
+    seqread = require("seqreadtape")
     seqread.prepare(fullFilePathStr)
     seqread.seek(0)
 } else {
-    seqread = seqreadserial
+    seqread = require("seqread")
     seqread.prepare(fullFilePathStr)
 }
 
@@ -686,33 +685,20 @@ try {
             else if (packetType === TAV_PACKET_IFRAME || packetType === TAV_PACKET_PFRAME) {
                 // Video packet
                 const compressedSize = seqread.readInt()
-                const isKeyframe = (packetType === TAV_PACKET_IFRAME)
 
                 // Read compressed tile data
                 let compressedPtr = seqread.readBytes(compressedSize)
                 updateDataRateBin(compressedSize)
 
-                let actualSize
-                let decompressStart = sys.nanoTime()
                 try {
-                    // Use gzip decompression (only compression format supported in TSVM JS)
-                    actualSize = gzip.decompFromTo(compressedPtr, compressedSize, blockDataPtr)
-                    decompressTime = (sys.nanoTime() - decompressStart) / 1000000.0
-                } catch (e) {
-                    decompressTime = (sys.nanoTime() - decompressStart) / 1000000.0
-                    console.log(`Frame ${frameCount}: Gzip decompression failed, skipping (compressed size: ${compressedSize}, error: ${e})`)
-                    sys.free(compressedPtr)
-                    continue
-                }
-
-                try {
-//                    serial.println(actualSize)
                     let decodeStart = sys.nanoTime()
 
-                    // Call TAV hardware decoder (like TEV's tevDecode but with RGB buffer outputs)
-                    graphics.tavDecode(
-                        blockDataPtr,
-                        CURRENT_RGB_ADDR, PREV_RGB_ADDR,  // RGB buffer pointers (not float arrays!)
+                    // Call new TAV hardware decoder that handles Zstd decompression internally
+                    // Note: No longer using JS gzip.decompFromTo - Kotlin handles Zstd natively
+                    graphics.tavDecodeCompressed(
+                        compressedPtr,             // Pass compressed data directly
+                        compressedSize,            // Size of compressed data
+                        CURRENT_RGB_ADDR, PREV_RGB_ADDR,  // RGB buffer pointers
                         header.width, header.height,
                         header.qualityLevel, header.qualityY, header.qualityCo, header.qualityCg,
                         frameCount,
@@ -723,6 +709,7 @@ try {
                     )
 
                     decodeTime = (sys.nanoTime() - decodeStart) / 1000000.0
+                    decompressTime = 0  // Decompression time now included in decode time
 
                     // Upload RGB buffer to display framebuffer (like TEV)
                     let uploadStart = sys.nanoTime()

tsvm_core/src/net/torvald/tsvm/GraphicsJSR223Delegate.kt

@@ -73,6 +73,8 @@ import kotlin.text.format
 import kotlin.text.lowercase
 import kotlin.text.toString
 import kotlin.times
+import io.airlift.compress.zstd.ZstdInputStream
+import java.io.ByteArrayInputStream
 
 class GraphicsJSR223Delegate(private val vm: VM) {
 
@@ -4137,6 +4139,53 @@ class GraphicsJSR223Delegate(private val vm: VM) {
     private val tavDebugFrameTarget = -1 // use negative number to disable the debug print
     private var tavDebugCurrentFrameNumber = 0
 
+    // New tavDecode function that accepts compressed data and decompresses internally
+    fun tavDecodeCompressed(compressedDataPtr: Long, compressedSize: Int, currentRGBAddr: Long, prevRGBAddr: Long,
+                           width: Int, height: Int, qIndex: Int, qYGlobal: Int, qCoGlobal: Int, qCgGlobal: Int, frameCount: Int,
+                           waveletFilter: Int = 1, decompLevels: Int = 6, isLossless: Boolean = false, tavVersion: Int = 1) {
+
+        // Read compressed data from VM memory into byte array
+        val compressedData = ByteArray(compressedSize)
+        for (i in 0 until compressedSize) {
+            compressedData[i] = vm.peek(compressedDataPtr + i)!!.toByte()
+        }
+
+        try {
+            // Decompress using Zstd
+            val bais = ByteArrayInputStream(compressedData)
+            val zis = ZstdInputStream(bais)
+            val decompressedData = zis.readBytes()
+            zis.close()
+            bais.close()
+
+            // Allocate buffer for decompressed data
+            val decompressedBuffer = vm.malloc(decompressedData.size)
+
+            try {
+                // Copy decompressed data to unsafe buffer
+                UnsafeHelper.memcpyRaw(
+                    decompressedData, UnsafeHelper.getArrayOffset(decompressedData),
+                    null, vm.usermem.ptr + decompressedBuffer.toLong(),
+                    decompressedData.size.toLong()
+                )
+
+                // Call the existing tavDecode function with decompressed data
+                tavDecode(decompressedBuffer.toLong(), currentRGBAddr, prevRGBAddr,
+                         width, height, qIndex, qYGlobal, qCoGlobal, qCgGlobal, frameCount,
+                         waveletFilter, decompLevels, isLossless, tavVersion)
+
+            } finally {
+                // Clean up allocated buffer
+                vm.free(decompressedBuffer)
+            }
+
+        } catch (e: Exception) {
+            println("TAV Zstd decompression error: ${e.message}")
+            throw e
+        }
+    }
+
+    // Original tavDecode function for backward compatibility (now handles decompressed data)
     fun tavDecode(blockDataPtr: Long, currentRGBAddr: Long, prevRGBAddr: Long,
                   width: Int, height: Int, qIndex: Int, qYGlobal: Int, qCoGlobal: Int, qCgGlobal: Int, frameCount: Int,
                   waveletFilter: Int = 1, decompLevels: Int = 6, isLossless: Boolean = false, tavVersion: Int = 1) {