diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 4c2254ab..9553ea9c 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -822,11 +822,13 @@ static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
                                       ZSTD_compResetPolicy_e const crp,
                                       ZSTD_buffered_policy_e const zbuff)
 {
+    DEBUGLOG(4, "ZSTD_resetCCtx_internal");
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
+    DEBUGLOG(4, "pledgedSrcSize: %u", (U32)pledgedSrcSize);
 
     if (crp == ZSTDcrp_continue) {
         if (ZSTD_equivalentParams(params, zc->appliedParams)) {
-            DEBUGLOG(5, "ZSTD_equivalentParams()==1");
+            DEBUGLOG(4, "ZSTD_equivalentParams()==1");
             assert(!(params.ldmParams.enableLdm &&
                      params.ldmParams.hashEveryLog == ZSTD_LDM_HASHEVERYLOG_NOTSET));
             zc->entropy->hufCTable_repeatMode = HUF_repeat_none;
@@ -2011,8 +2013,6 @@ static size_t ZSTD_compressBegin_internal(ZSTD_CCtx* cctx,
                                    ZSTD_buffered_policy_e zbuff)
 {
     DEBUGLOG(4, "ZSTD_compressBegin_internal");
-    DEBUGLOG(4, "dict ? %s", dict ? "dict" : (cdict ? "cdict" : "none"));
-    DEBUGLOG(4, "dictMode : %u", (U32)dictMode);
     /* params are supposed to be fully validated at this point */
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
     assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
@@ -2485,7 +2485,7 @@ size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize)
     ZSTD_CCtx_params params = zcs->requestedParams;
     params.fParams.contentSizeFlag = (pledgedSrcSize > 0);
     params.cParams = ZSTD_getCParamsFromCCtxParams(params, pledgedSrcSize, 0);
-    DEBUGLOG(5, "ZSTD_resetCStream");
+    DEBUGLOG(4, "ZSTD_resetCStream");
     return ZSTD_resetCStream_internal(zcs, NULL, 0, ZSTD_dm_auto, zcs->cdict, params, pledgedSrcSize);
 }
 
@@ -2497,6 +2497,7 @@ size_t ZSTD_initCStream_internal(ZSTD_CStream* zcs,
                     const void* dict, size_t dictSize, const ZSTD_CDict* cdict,
                     ZSTD_CCtx_params params, unsigned long long pledgedSrcSize)
 {
+    DEBUGLOG(4, "ZSTD_initCStream_internal");
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
     assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
 
@@ -2768,6 +2769,7 @@ size_t ZSTD_compress_generic (ZSTD_CCtx* cctx,
                 cctx->requestedParams, cctx->pledgedSrcSizePlusOne-1, 0 /*dictSize*/);
         memset(&cctx->prefixDict, 0, sizeof(cctx->prefixDict));  /* single usage */
         assert(prefixDict.dict==NULL || cctx->cdict==NULL);   /* only one can be set */
+        DEBUGLOG(4, "ZSTD_compress_generic : transparent init stage");
 
 #ifdef ZSTD_MULTITHREAD
         if (params.nbThreads > 1) {
diff --git a/programs/fileio.c b/programs/fileio.c
index 9c5e2c40..76726b47 100644
--- a/programs/fileio.c
+++ b/programs/fileio.c
@@ -757,6 +757,7 @@ static int FIO_compressFilename_internal(cRess_t ress,
     U64 readsize = 0;
     U64 compressedfilesize = 0;
     U64 const fileSize = UTIL_getFileSize(srcFileName);
+    DISPLAYLEVEL(5, "%s: %u bytes \n", srcFileName, (U32)fileSize);
 
     switch (g_compressionType) {
         case FIO_zstdCompression:
@@ -796,7 +797,7 @@ static int FIO_compressFilename_internal(cRess_t ress,
 
     /* init */
 #ifdef ZSTD_NEWAPI
-    /* nothing, reset is implied */
+    CHECK( ZSTD_resetCStream(ress.cctx, fileSize) );  /* to pass fileSize */
 #elif defined(ZSTD_MULTITHREAD)
     CHECK( ZSTDMT_resetCStream(ress.cctx, fileSize) );
 #else
@@ -849,10 +850,10 @@ static int FIO_compressFilename_internal(cRess_t ress,
 
     /* End of Frame */
     {   size_t result = 1;
-        while (result!=0) {   /* note : is there any possibility of endless loop ? */
+        while (result != 0) {
             ZSTD_outBuffer outBuff = { ress.dstBuffer, ress.dstBufferSize, 0 };
 #ifdef ZSTD_NEWAPI
-            ZSTD_inBuffer inBuff = { NULL, 0, 0};
+            ZSTD_inBuffer inBuff = { NULL, 0, 0 };
             result = ZSTD_compress_generic(ress.cctx,
                         &outBuff, &inBuff, ZSTD_e_end);
 #elif defined(ZSTD_MULTITHREAD)
@@ -863,8 +864,10 @@ static int FIO_compressFilename_internal(cRess_t ress,
             if (ZSTD_isError(result))
                 EXM_THROW(26, "Compression error during frame end : %s",
                             ZSTD_getErrorName(result));
-            { size_t const sizeCheck = fwrite(ress.dstBuffer, 1, outBuff.pos, dstFile);
-              if (sizeCheck!=outBuff.pos) EXM_THROW(27, "Write error : cannot write frame end into %s", dstFileName); }
+            {   size_t const sizeCheck = fwrite(ress.dstBuffer, 1, outBuff.pos, dstFile);
+                if (sizeCheck!=outBuff.pos)
+                    EXM_THROW(27, "Write error : cannot write frame end into %s", dstFileName);
+            }
             compressedfilesize += outBuff.pos;
         }
     }
@@ -974,7 +977,7 @@ int FIO_compressMultipleFilenames(const char** inFileNamesTable, unsigned nbFile
     char*  dstFileName = (char*)malloc(FNSPACE);
     size_t const suffixSize = suffix ? strlen(suffix) : 0;
     U64 const srcSize = (nbFiles != 1) ? 0 : UTIL_getFileSize(inFileNamesTable[0]) ;
-    int const isRegularFile = (nbFiles > 1) ? 0 : UTIL_isRegularFile(inFileNamesTable[0]);  /* won't write frame content size when nbFiles > 1 */
+    int const isRegularFile = (nbFiles > 1) ? 1 : UTIL_isRegularFile(inFileNamesTable[0]);  /* if nbFiles > 1, it's not stdin */
     cRess_t ress = FIO_createCResources(dictFileName, compressionLevel, srcSize, isRegularFile, comprParams);
 
     /* init */