Remove LZ4 compression — negligible benefit on delta data

Delta-compressed entity/playerState bitstreams have minimal
redundancy for LZ4 to exploit. The per-block 8-byte header
overhead was comparable to the compression savings.

Removed: lz4.h include, SVD_WriteBlock/ReadBlock functions,
SVDEMO_FLAG_COMPRESSED, demo.compressed field, svdemo_compress
cvar, lz4.c from build. Direct size+data writes replace block I/O.

Demo format v3 (flags field reserved, always 0).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

code/quake3.vcxproj

@@ -997,8 +997,6 @@
     </ClCompile>
     <ClCompile Include="server\sv_netdemo.c">
     </ClCompile>
-    <ClCompile Include="server\lz4.c">
-    </ClCompile>
     <ClCompile Include="server\sv_world.c">
       <Optimization Condition="'$(Configuration)|$(Platform)'=='Debug TA DEMO|Win32'">Disabled</Optimization>
       <BrowseInformation Condition="'$(Configuration)|$(Platform)'=='Debug TA DEMO|Win32'">true</BrowseInformation>

code/server/sv_init.c

@@ -623,7 +623,6 @@ void SV_Init (void) {
 
 	// server-side demo settings
 	Cvar_Get ("svdemo_autorecord", "0", CVAR_ARCHIVE);
-	Cvar_Get ("svdemo_compress", "1", CVAR_ARCHIVE);
 	Cvar_Get ("svdemo_pauseEmpty", "1", CVAR_ARCHIVE);
 
 	// initialize bot cvars so they are listed and can be set before loading the botlib

code/server/sv_netdemo.c

@@ -10,7 +10,6 @@ snapshot pipeline delivers them to a spectator client.
 */
 
 #include "server.h"
-#include "lz4.h"
 
 // ---------------------------------------------------------------
 //  File format
@@ -55,7 +54,6 @@ snapshot pipeline delivers them to a spectator client.
 #define SVDEMO_MAX_MAPNAME	64
 
 // header flags
-#define SVDEMO_FLAG_COMPRESSED	1	// per-frame data is LZ4 compressed
 
 // ---------------------------------------------------------------
 //  State
@@ -81,7 +79,6 @@ typedef struct {
 	// recording
 	fileHandle_t	recordFile;
 	qboolean		recording;
-	qboolean		compressed;			// LZ4 compression enabled
 	char			*lastConfigstrings[MAX_CONFIGSTRINGS];  // for delta detection
 	svdEntityState_t	prevEntities[MAX_GENTITIES];  // previous frame for delta
 	svdPlayerState_t	prevPlayers[MAX_CLIENTS];     // previous frame player states
@@ -131,58 +128,6 @@ static short SVD_ReadShort( fileHandle_t f ) {
 	return v;
 }
 
-// ---------------------------------------------------------------
-//  LZ4 block I/O: writes [uncompressed_size][compressed_size][data]
-// ---------------------------------------------------------------
-
-static void SVD_WriteBlock( fileHandle_t f, const byte *data, int len ) {
-	if ( demo.compressed && len > 0 ) {
-		int bound = LZ4_compressBound( len );
-		static byte compBuf[MAX_GENTITIES * 300];
-		int compLen;
-
-		compLen = LZ4_compress_default( (const char *)data, (char *)compBuf, len, bound );
-		if ( compLen > 0 ) {
-			SVD_WriteInt( f, len );			// original size
-			SVD_WriteInt( f, compLen );		// compressed size
-			FS_Write( compBuf, compLen, f );
-			return;
-		}
-		// fall through to uncompressed on failure
-	}
-	SVD_WriteInt( f, len );		// original size
-	SVD_WriteInt( f, 0 );		// 0 = not compressed
-	FS_Write( data, len, f );
-}
-
-static int SVD_ReadBlock( fileHandle_t f, byte *buf, int bufSize ) {
-	int origLen, compLen;
-
-	origLen = SVD_ReadInt( f );
-	compLen = SVD_ReadInt( f );
-
-	if ( origLen <= 0 || origLen > bufSize ) {
-		return -1;
-	}
-
-	if ( compLen > 0 ) {
-		// compressed
-		static byte compBuf[MAX_GENTITIES * 300];
-		if ( compLen > (int)sizeof(compBuf) ) {
-			return -1;
-		}
-		FS_Read( compBuf, compLen, f );
-		if ( LZ4_decompress_safe( (const char *)compBuf, (char *)buf, compLen, bufSize ) != origLen ) {
-			return -1;
-		}
-	} else {
-		// uncompressed
-		FS_Read( buf, origLen, f );
-	}
-
-	return origLen;
-}
-
 // ---------------------------------------------------------------
 //  Write header
 // ---------------------------------------------------------------
@@ -193,7 +138,7 @@ static void SVD_WriteHeader( fileHandle_t f ) {
 
 	SVD_WriteInt( f, SVDEMO_MAGIC );
 	SVD_WriteInt( f, SVDEMO_VERSION );
-	SVD_WriteInt( f, demo.compressed ? SVDEMO_FLAG_COMPRESSED : 0 );
+	SVD_WriteInt( f, 0 );  // flags (reserved)
 	SVD_WriteInt( f, sv_maxclients->integer );
 	SVD_WriteInt( f, sv_fps->integer );
 
@@ -294,8 +239,9 @@ static void SVD_WriteFrame( fileHandle_t f ) {
 	// end of entities marker
 	MSG_WriteBits( &msg, (MAX_GENTITIES - 1), GENTITYNUM_BITS );
 
-	// write entity message to file (optionally LZ4 compressed)
+	// write entity message to file
-	SVD_WriteBlock( f, msg.data, msg.cursize );
+	SVD_WriteInt( f, msg.cursize );
+	FS_Write( msg.data, msg.cursize, f );
 
 	// write player states (delta compressed)
 	{
@@ -346,7 +292,8 @@ static void SVD_WriteFrame( fileHandle_t f ) {
 		MSG_WriteBits( &psmsg, MAX_CLIENTS - 1, 6 );
 		MSG_WriteBits( &psmsg, 0, 1 );
 
-		SVD_WriteBlock( f, psmsg.data, psmsg.cursize );
+		SVD_WriteInt( f, psmsg.cursize );
+		FS_Write( psmsg.data, psmsg.cursize, f );
 	}
 
 	// configstring changes
@@ -417,10 +364,8 @@ static qboolean SVD_StartRecording( const char *demoname ) {
 		return qfalse;
 	}
 
-	Com_Printf( "Recording server demo to %s%s\n", path,
+	Com_Printf( "Recording server demo to %s\n", path );
-		Cvar_VariableIntegerValue("svdemo_compress") ? " (LZ4)" : "" );
 	demo.recording = qtrue;
-	demo.compressed = Cvar_VariableIntegerValue("svdemo_compress") ? qtrue : qfalse;
 
 	// clear delta state for fresh recording
 	Com_Memset( demo.prevEntities, 0, sizeof(demo.prevEntities) );
@@ -567,10 +512,7 @@ static qboolean SVD_ReadHeader( fileHandle_t f ) {
 		return qfalse;
 	}
 
-	{
+	SVD_ReadInt( f );  // flags (reserved)
-		int flags = SVD_ReadInt( f );
-		demo.compressed = ( flags & SVDEMO_FLAG_COMPRESSED ) ? qtrue : qfalse;
-	}
 
 	demo.playMaxClients = SVD_ReadInt( f );
 	demo.playFps = SVD_ReadInt( f );
@@ -661,11 +603,12 @@ static qboolean SVD_ReadFrame( fileHandle_t f ) {
 		}
 	}
 
-	// read entity message (optionally LZ4 compressed)
+	// read entity message
-	blockLen = SVD_ReadBlock( f, msgBuf, sizeof(msgBuf) );
+	blockLen = SVD_ReadInt( f );
-	if ( blockLen <= 0 ) {
+	if ( blockLen <= 0 || blockLen > (int)sizeof(msgBuf) ) {
 		return qfalse;
 	}
+	FS_Read( msgBuf, blockLen, f );
 	MSG_Init( &msg, msgBuf, sizeof(msgBuf) );
 	msg.cursize = blockLen;
 
@@ -735,8 +678,9 @@ static qboolean SVD_ReadFrame( fileHandle_t f ) {
 		static byte psBuf[MAX_CLIENTS * 600];  // worst case: full playerState from baseline
 		int psMsgLen;
 
-		psMsgLen = SVD_ReadBlock( f, psBuf, sizeof(psBuf) );
+		psMsgLen = SVD_ReadInt( f );
-		if ( psMsgLen > 0 ) {
+		if ( psMsgLen > 0 && psMsgLen <= (int)sizeof(psBuf) ) {
+			FS_Read( psBuf, psMsgLen, f );
 			MSG_Init( &psmsg, psBuf, sizeof(psBuf) );
 			psmsg.cursize = psMsgLen;