diff --git a/apps/decoder.c b/apps/decoder.c
index 82202289ef4d27d903b0167379f1424f510b5d1b..458c164ac83cb6f9ea949206acf5468a341e8213 100644
--- a/apps/decoder.c
+++ b/apps/decoder.c
@@ -179,13 +179,24 @@ static bool parseCmdlIVAS_dec( int16_t argc, char **argv, DecArguments *arg );
 static void usage_dec( void );
 static ivas_error decodeG192( DecArguments arg, BS_READER_HANDLE hBsReader, IVAS_DEC_HRTF_BINARY_WRAPPER *hHrtfBinary, RotFileReader *headRotReader, RotFileReader *externalOrientationFileReader, RotFileReader *refRotReader, Vector3PairFileReader *referenceVectorReader, ObjectEditFileReader *objectEditFileReader, ISAR_SPLIT_REND_BITS_DATA *splitRendBits, IVAS_DEC_HANDLE hIvasDec, int16_t *pcmBuf );
 #ifdef FIX_1119_SPLIT_RENDERING_VOIP
+#ifdef DECODER_FORMAT_SWITCHING
+static ivas_error decodeVoIP( DecArguments arg, BS_READER_HANDLE hBsReader, IVAS_DEC_HRTF_BINARY_WRAPPER *hHrtf, RotFileReader *headRotReader, RotFileReader *externalOrientationFileReader, RotFileReader *refRotReader, Vector3PairFileReader *referenceVectorReader, ObjectEditFileReader *objectEditFileReader, ISAR_SPLIT_REND_BITS_DATA *splitRendBits, IVAS_DEC_HANDLE *phIvasDec, int16_t *pcmBuf );
+#else
 static ivas_error decodeVoIP( DecArguments arg, BS_READER_HANDLE hBsReader, IVAS_DEC_HRTF_BINARY_WRAPPER *hHrtf, RotFileReader *headRotReader, RotFileReader *externalOrientationFileReader, RotFileReader *refRotReader, Vector3PairFileReader *referenceVectorReader, ObjectEditFileReader *objectEditFileReader, ISAR_SPLIT_REND_BITS_DATA *splitRendBits, IVAS_DEC_HANDLE hIvasDec, int16_t *pcmBuf );
+#endif
+#else
+#ifdef DDECODER_FORMAT_SWITCHING
+static ivas_error decodeVoIP( DecArguments arg, BS_READER_HANDLE hBsReader, IVAS_DEC_HRTF_BINARY_WRAPPER *hHrtfBinary, RotFileReader *headRotReader, RotFileReader *externalOrientationFileReader, RotFileReader *refRotReader, Vector3PairFileReader *referenceVectorReader, ObjectEditFileReader *objectEditFileReader, IVAS_DEC_HANDLE *phIvasDec, int16_t *pcmBuf );
 #else
 static ivas_error decodeVoIP( DecArguments arg, BS_READER_HANDLE hBsReader, IVAS_DEC_HRTF_BINARY_WRAPPER *hHrtfBinary, RotFileReader *headRotReader, RotFileReader *externalOrientationFileReader, RotFileReader *refRotReader, Vector3PairFileReader *referenceVectorReader, ObjectEditFileReader *objectEditFileReader, IVAS_DEC_HANDLE hIvasDec, int16_t *pcmBuf );
 #endif
+#endif
 static ivas_error load_hrtf_from_file( IVAS_DEC_HRTF_BINARY_WRAPPER *hHrtfBinary, IVAS_DEC_HANDLE hIvasDec, const IVAS_AUDIO_CONFIG OutputConfig, const int32_t output_Fs );
 static void do_object_editing_fx( IVAS_EDITABLE_PARAMETERS *editableParameters, ObjectEditFileReader *objectEditFileReader );
 
+#ifdef DECODER_FORMAT_SWITCHING
+static ivas_error restartDecoder( IVAS_DEC_HANDLE *phIvasDec, IVAS_DEC_MODE codec, DecArguments *arg, IVAS_RENDER_CONFIG_DATA *renderConfig, IVAS_CUSTOM_LS_DATA *hLsCustomData );
+#endif
 
 /*------------------------------------------------------------------------------------------*
  * main()
@@ -720,9 +731,17 @@ int main(
     if ( arg.voipMode )
     {
 #ifdef FIX_1119_SPLIT_RENDERING_VOIP
+#ifdef DECODER_FORMAT_SWITCHING
+        error = decodeVoIP( arg, hBsReader, &hHrtfBinary, headRotReader, externalOrientationFileReader, refRotReader, referenceVectorReader, objectEditFileReader, &splitRendBits, &hIvasDec, pcmBuf );
+#else
         error = decodeVoIP( arg, hBsReader, &hHrtfBinary, headRotReader, externalOrientationFileReader, refRotReader, referenceVectorReader, objectEditFileReader, &splitRendBits, hIvasDec, pcmBuf );
+#endif
+#else
+#ifdef DDECODER_FORMAT_SWITCHING
+        error = decodeVoIP( arg, hBsReader, &hHrtfBinary, headRotReader, externalOrientationFileReader, refRotReader, referenceVectorReader, objectEditFileReader, &hIvasDec, pcmBuf );
 #else
         error = decodeVoIP( arg, hBsReader, &hHrtfBinary, headRotReader, externalOrientationFileReader, refRotReader, referenceVectorReader, objectEditFileReader, hIvasDec, pcmBuf );
+#endif
 #endif
     }
     else
@@ -2990,7 +3009,11 @@ static ivas_error decodeVoIP(
 #ifdef FIX_1119_SPLIT_RENDERING_VOIP
     ISAR_SPLIT_REND_BITS_DATA *splitRendBits,
 #endif
+#ifdef DECODER_FORMAT_SWITCHING
+    IVAS_DEC_HANDLE *phIvasDec,
+#else
     IVAS_DEC_HANDLE hIvasDec,
+#endif
     int16_t *pcmBuf )
 {
     bool decodingFailed = true; /* Assume failure until cleanup is reached without errors */
@@ -3022,6 +3045,9 @@ static ivas_error decodeVoIP(
     int16_t delayNumSamples = -1;
     int32_t delayTimeScale = -1;
     int16_t i;
+#ifdef DECODER_FORMAT_SWITCHING
+    IVAS_DEC_HANDLE hIvasDec = *phIvasDec;
+#endif
 #ifdef IVAS_RTPDUMP
     IVAS_RTP ivasRtp = { 0 };
     IVAS_RTP srRtp = { 0 };
@@ -3216,6 +3242,27 @@ static ivas_error decodeVoIP(
     {
         nSamplesRendered = 0;
 
+#ifdef DECODER_FORMAT_SWITCHING
+        if ( ivasRtp.restartNeeded )
+        {
+            IVAS_DEC_MODE newCodecInPacket = ( ivasRtp.codecId == IVAS_RTP_EVS ) ? IVAS_DEC_MODE_EVS : IVAS_DEC_MODE_IVAS;
+            error = restartDecoder(
+                &hIvasDec,
+                newCodecInPacket,
+                &arg,
+                NULL, /* ToDo : Provide rendererConfig */
+                NULL  /* ToDo : Provide LS Custom Data */
+            );
+            if ( error != IVAS_ERR_OK )
+            {
+                fprintf( stderr, "\nFailed to restart decoder from %d to %d\n", arg.decMode, newCodecInPacket );
+                goto cleanup;
+            }
+            *phIvasDec = hIvasDec; /* Update for main()' s free */
+            ivasRtp.restartNeeded = false;
+        }
+#endif
+
         /* reference vector */
         if ( arg.enableReferenceVectorTracking && vec_pos_update == 0 )
         {
@@ -3471,6 +3518,31 @@ static ivas_error decodeVoIP(
 
                 /* Placeholder for memory reallocation */
                 /* ... */
+#ifdef DECODER_FORMAT_SWITCHING
+                if ( IVAS_DEC_isRestartNeeded( hIvasDec ) )
+                {
+                    IVAS_DEC_BS_FORMAT tempFormat;
+                    if ( ( error = IVAS_DEC_GetFormat( hIvasDec, &tempFormat ) ) != IVAS_ERR_OK )
+                    {
+                        fprintf( stderr, "\nError in IVAS_DEC_GetFormat, code: %d\n", error );
+                        goto cleanup;
+                    }
+                    IVAS_DEC_MODE codecMode = ( tempFormat == IVAS_DEC_BS_MONO ) ? IVAS_DEC_MODE_EVS : IVAS_DEC_MODE_IVAS;
+                    error = restartDecoder(
+                        &hIvasDec,
+                        codecMode,
+                        &arg,
+                        NULL, /* ToDo : Provide rendererConfig */
+                        NULL  /* ToDo : Provide LS Custom Data */
+                    );
+                    if ( error != IVAS_ERR_OK )
+                    {
+                        fprintf( stderr, "\nFailed to restart decoder\n" );
+                        goto cleanup;
+                    }
+                    *phIvasDec = hIvasDec; /* Update for main()' s free */
+                }
+#endif
 
                 /* Load HRTF binary file data */
                 if ( arg.hrtfReaderEnabled )
@@ -4248,4 +4320,118 @@ static ivas_error load_hrtf_from_file(
     return IVAS_ERR_OK;
 }
 
+#ifdef DECODER_FORMAT_SWITCHING
+
+ivas_error restartDecoder(
+    IVAS_DEC_HANDLE *phIvasDec,
+    IVAS_DEC_MODE codec,
+    DecArguments *arg,
+    IVAS_RENDER_CONFIG_DATA *renderConfig,
+    IVAS_CUSTOM_LS_DATA *hLsCustomData )
+{
+    ivas_error error = IVAS_ERR_OK;
+    IVAS_DEC_HANDLE hIvasDec;
+
+    if ( phIvasDec == NULL )
+    {
+        return IVAS_ERR_UNEXPECTED_NULL_POINTER;
+    }
+
+    if ( NULL != *phIvasDec )
+    {
+        IVAS_DEC_Close( phIvasDec );
+    }
+
+    if ( ( error = IVAS_DEC_Open( phIvasDec, codec ) ) != IVAS_ERR_OK )
+    {
+        fprintf( stderr, "Open failed: %s\n", IVAS_DEC_GetErrorMessage( error ) );
+        goto cleanup;
+    }
+
+    arg->decMode = codec;
+
+    hIvasDec = *phIvasDec;
+
+    uint16_t aeID = arg->aeSequence.count > 0 ? arg->aeSequence.pID[0] : 65535;
+
+    IVAS_AUDIO_CONFIG outputConfig = ( codec == IVAS_DEC_MODE_IVAS ) ? arg->outputConfig : IVAS_AUDIO_CONFIG_MONO;
+#ifdef FIX_1318_ROOM_SIZE_CMD_LINE
+    if ( ( error = IVAS_DEC_Configure( hIvasDec, arg->output_Fs, outputConfig, arg->renderFramesize, arg->customLsOutputEnabled, arg->hrtfReaderEnabled,
+                                       arg->enableHeadRotation, arg->enableExternalOrientation, arg->orientation_tracking, arg->renderConfigEnabled, arg->roomSize, arg->non_diegetic_pan_enabled,
+                                       arg->non_diegetic_pan_gain_fx, arg->dpidEnabled, aeID, arg->objEditEnabled, arg->delayCompensationEnabled ) ) != IVAS_ERR_OK )
+#else
+    if ( ( error = IVAS_DEC_Configure( hIvasDec, arg->output_Fs, outputConfig, arg->renderFramesize, arg->customLsOutputEnabled, arg->hrtfReaderEnabled,
+                                       arg->enableHeadRotation, arg->enableExternalOrientation, arg->orientation_tracking, arg->renderConfigEnabled, arg->non_diegetic_pan_enabled,
+                                       arg->non_diegetic_pan_gain_fx, arg->dpidEnabled, aeID, arg->objEditEnabled, arg->delayCompensationEnabled ) ) != IVAS_ERR_OK )
+#endif
+    {
+        fprintf( stderr, "\nConfigure failed: %s\n\n", IVAS_DEC_GetErrorMessage( error ) );
+        goto cleanup;
+    }
+
+    if ( ( error = IVAS_DEC_GetRenderFramesize( hIvasDec, &arg->renderFramesize ) ) != IVAS_ERR_OK )
+    {
+        fprintf( stderr, "\nConfigure failed: %s\n\n", IVAS_DEC_GetErrorMessage( error ) );
+        goto cleanup;
+    }
+
+    if ( arg->outputConfig == IVAS_AUDIO_CONFIG_BINAURAL_SPLIT_CODED || arg->outputConfig == IVAS_AUDIO_CONFIG_BINAURAL_SPLIT_PCM )
+    {
+        if ( ( error = IVAS_DEC_EnableSplitRendering( hIvasDec ) ) != IVAS_ERR_OK )
+        {
+            fprintf( stderr, "\nSplit rendering configure failed: %s\n\n", IVAS_DEC_GetErrorMessage( error ) );
+            goto cleanup;
+        }
+
+        if ( ( error = IVAS_DEC_GetRenderFramesize( hIvasDec, &arg->renderFramesize ) ) != IVAS_ERR_OK )
+        {
+            fprintf( stderr, "\nConfigure failed: %s\n\n", IVAS_DEC_GetErrorMessage( error ) );
+            goto cleanup;
+        }
+
+        arg->enableHeadRotation = true;
+    }
+
+    if ( arg->voipMode )
+    {
+        if ( ( error = IVAS_DEC_EnableVoIP( hIvasDec, 60, arg->inputFormat ) ) != IVAS_ERR_OK )
+        {
+            fprintf( stderr, "\nCould not enable VOIP: %s\n\n", IVAS_DEC_GetErrorMessage( error ) );
+            goto cleanup;
+        }
+    }
+
+    if ( ( error = IVAS_DEC_PrintConfig( hIvasDec, 1, arg->voipMode ) ) != IVAS_ERR_OK )
+    {
+        fprintf( stderr, "\nIVAS_DEC_PrintConfig failed: %s\n\n", IVAS_DEC_GetErrorMessage( error ) );
+        goto cleanup;
+    }
+
+    if ( arg->renderConfigEnabled && renderConfig != NULL )
+    {
+        if ( ( error = IVAS_DEC_FeedRenderConfig( hIvasDec, *renderConfig ) ) != IVAS_ERR_OK )
+        {
+            fprintf( stderr, "\nIVAS_DEC_FeedRenderConfig failed: %s\n\n", IVAS_DEC_GetErrorMessage( error ) );
+            goto cleanup;
+        }
+    }
+
+    if ( arg->customLsOutputEnabled && hLsCustomData != NULL )
+    {
+        if ( ( error = IVAS_DEC_FeedCustomLsData( hIvasDec, *hLsCustomData ) ) != IVAS_ERR_OK )
+        {
+            fprintf( stderr, "\nIVAS_DEC_FeedCustomLsData failed: %s\n", IVAS_DEC_GetErrorMessage( error ) );
+            goto cleanup;
+        }
+    }
+
+    return IVAS_ERR_OK;
+
+cleanup:
+    IVAS_DEC_Close( phIvasDec );
+    return error;
+}
+
+#endif
+
 #undef WMC_TOOL_SKIP
diff --git a/lib_com/ivas_prot_fx.h b/lib_com/ivas_prot_fx.h
index 0e607039f7cb35642d8181270e953354be7d227c..0cb0174d691783bc653a12359861190a292acb61 100644
--- a/lib_com/ivas_prot_fx.h
+++ b/lib_com/ivas_prot_fx.h
@@ -4030,7 +4030,12 @@ ivas_error ivas_output_buff_dec_fx(
 );
 
 ivas_error ivas_dec_get_format_fx(
+#ifdef DECODER_FORMAT_SWITCHING
+    Decoder_Struct *st_ivas,                                    /* i/o: IVAS decoder structure                      */
+    const bool isVoipMode                                       /* i  : voip mode indicator                         */
+#else
     Decoder_Struct *st_ivas                                     /* i/o: IVAS decoder structure                      */
+#endif
 );
 
 ivas_error ivas_dec_setup(
diff --git a/lib_com/options.h b/lib_com/options.h
index f06deff8c79775b0d3a819c40a61694153064b1a..b6d1ca2b647e22dd5a1e7ac4d3b57b274e472264 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -169,6 +169,7 @@
 #define ISM_PI_DATA                                    /* Add reading and packing/unpacking of ISM PI data */
 #define REVERSE_ISM_PI_DATA                            /* Add reading and packing/unpacking of reverse ISM PI data */
 #define PI_LATENCY                                     /* Support for PI latency */
+#define DECODER_FORMAT_SWITCHING                       /* Re-initialize the decoder when the format/subformat of the incoming stream is changed */
 
 /* #################### End BASOP porting switches ############################ */
 
diff --git a/lib_dec/ivas_init_dec_fx.c b/lib_dec/ivas_init_dec_fx.c
index 5300b598b50bf9cb3941820f240f5dfe09e737e6..984f02ece1139d7654e2b95bec5b25f5147b3e59 100644
--- a/lib_dec/ivas_init_dec_fx.c
+++ b/lib_dec/ivas_init_dec_fx.c
@@ -104,7 +104,12 @@ static AUDIO_CONFIG ivas_set_audio_config_from_sba_order(
  *---------------------------------------------------------------------*/
 
 ivas_error ivas_dec_get_format_fx(
+#ifdef DECODER_FORMAT_SWITCHING
+    Decoder_Struct *st_ivas, /* i/o: IVAS decoder structure    */
+    const bool isVoipMode    /* i  : voip mode indicator       */
+#else
     Decoder_Struct *st_ivas /* i/o: IVAS decoder structure     */
+#endif
 )
 {
     Word16 k, idx, num_bits_read;
@@ -142,10 +147,26 @@ ivas_error ivas_dec_get_format_fx(
         !( EQ_32( st_ivas->ivas_format, MASA_FORMAT ) && EQ_32( st_ivas->last_ivas_format, MASA_ISM_FORMAT ) ) &&
         !( EQ_32( st_ivas->ivas_format, MASA_ISM_FORMAT ) && EQ_32( st_ivas->last_ivas_format, MASA_FORMAT ) ) )
     {
+#ifdef DECODER_FORMAT_SWITCHING
+        IF( isVoipMode )
+        {
+            st_ivas->restartNeeded = 1;
+            move16();
+            return IVAS_ERR_OK;
+        }
+        ELSE
+        {
+#ifdef DEBUGGING
+            fprintf( stderr, "\nError: Changing the number of ISMs is not supported!\n" );
+#endif
+            return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong number of objects signalled!" );
+        }
+#else
 #ifdef DEBUGGING
         fprintf( stderr, "\nError: Changing the number of ISMs is not supported!\n" );
 #endif
         return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong number of objects signalled!" );
+#endif
     }
 
     /*-------------------------------------------------------------------*
@@ -183,10 +204,26 @@ ivas_error ivas_dec_get_format_fx(
             test();
             IF( st_ivas->ini_frame > 0 && NE_16( nchan_ism, st_ivas->nchan_ism ) )
             {
+#ifdef DECODER_FORMAT_SWITCHING
+                IF( isVoipMode )
+                {
+                    st_ivas->restartNeeded = 1;
+                    move16();
+                    return IVAS_ERR_OK;
+                }
+                ELSE
+                {
+#ifdef DEBUGGING
+                    fprintf( stderr, "\nError: Changing the number of ISMs is not supported!\n" );
+#endif
+                    return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong number of objects signalled!" );
+                }
+#else
 #ifdef DEBUGGING
                 fprintf( stderr, "\nError: Changing the number of ISMs is not supported!\n" );
 #endif
                 return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong number of objects signalled!" );
+#endif
             }
 
             st_ivas->nchan_ism = nchan_ism;
@@ -210,10 +247,26 @@ ivas_error ivas_dec_get_format_fx(
             test();
             IF( st_ivas->ini_frame > 0 && NE_16( sba_planar, st_ivas->sba_planar ) )
             {
+#ifdef DECODER_FORMAT_SWITCHING
+                IF( isVoipMode )
+                {
+                    st_ivas->restartNeeded = 1;
+                    move16();
+                    return IVAS_ERR_OK;
+                }
+                ELSE
+                {
+#ifdef DEBUGGING
+                    fprintf( stderr, "\nError: Changing the SBA planar/3D layout is not supported!\n" );
+#endif
+                    return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong SBA planar flag signalled!" );
+                }
+#else
 #ifdef DEBUGGING
                 fprintf( stderr, "\nError: Changing the SBA planar/3D layout is not supported!\n" );
 #endif
                 return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong SBA planar flag signalled!" );
+#endif
             }
 
             /* read Ambisonic (SBA) order */
@@ -224,10 +277,26 @@ ivas_error ivas_dec_get_format_fx(
             test();
             IF( st_ivas->ini_frame > 0 && NE_16( sba_order, st_ivas->sba_order ) )
             {
+#ifdef DECODER_FORMAT_SWITCHING
+                IF( isVoipMode )
+                {
+                    st_ivas->restartNeeded = 1;
+                    move16();
+                    return IVAS_ERR_OK;
+                }
+                ELSE
+                {
+#ifdef DEBUGGING
+                    fprintf( stderr, "\nError: Changing the SBA order is not supported!\n" );
+#endif
+                    return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong SBA order signalled!" );
+                }
+#else
 #ifdef DEBUGGING
                 fprintf( stderr, "\nError: Changing the SBA order is not supported!\n" );
 #endif
                 return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong SBA order signalled!" );
+#endif
             }
 
             sba_analysis_order = ivas_sba_get_analysis_order_fx( ivas_total_brate, sba_order );
@@ -235,10 +304,23 @@ ivas_error ivas_dec_get_format_fx(
         }
         ELSE IF( EQ_32( st_ivas->ivas_format, MASA_FORMAT ) )
         {
+#ifdef DECODER_FORMAT_SWITCHING
+            UWord8 masaRestartCandidate;
+            masaRestartCandidate = 0;
+            move16();
+#endif
             /* read number of MASA transport channels */
             k = extract_l( Mpy_32_32_r( ivas_total_brate, ONE_BY_FRAMES_PER_SEC_Q31 ) );
             IF( st_ivas->bit_stream[k - 1] )
             {
+#ifdef DECODER_FORMAT_SWITCHING
+                test();
+                IF( st_ivas->nchan_transport == 1 && isVoipMode )
+                {
+                    masaRestartCandidate = 1;
+                    move16();
+                }
+#endif
                 st_ivas->nchan_transport = 2;
                 move16();
                 element_mode_flag = 1;
@@ -246,6 +328,14 @@ ivas_error ivas_dec_get_format_fx(
             }
             ELSE
             {
+#ifdef DECODER_FORMAT_SWITCHING
+                test();
+                IF( st_ivas->nchan_transport == 2 && isVoipMode )
+                {
+                    masaRestartCandidate = 1;
+                    move16();
+                }
+#endif
                 st_ivas->nchan_transport = 1;
                 move16();
             }
@@ -279,14 +369,38 @@ ivas_error ivas_dec_get_format_fx(
                 element_mode_flag = 1;
                 move16();
             }
+#ifdef DECODER_FORMAT_SWITCHING
+            ELSE IF( masaRestartCandidate > 0 )
+            {
+                st_ivas->restartNeeded = 1;
+                move16();
+                return IVAS_ERR_OK;
+            }
+#endif
 
             test();
             IF( st_ivas->ini_frame > 0 && NE_16( nchan_ism, st_ivas->nchan_ism ) )
             {
+#ifdef DECODER_FORMAT_SWITCHING
+                IF( isVoipMode )
+                {
+                    st_ivas->restartNeeded = 1;
+                    move16();
+                    return IVAS_ERR_OK;
+                }
+                ELSE
+                {
+#ifdef DEBUGGING
+                    fprintf( stderr, "\nError: Changing the number of ISMs is not supported!\n" );
+#endif
+                    return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong number of objects signalled!" );
+                }
+#else
 #ifdef DEBUGGING
                 fprintf( stderr, "\nError: Changing the number of ISMs is not supported!\n" );
 #endif
                 return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong number of objects signalled!" );
+#endif
             }
 
             st_ivas->nchan_ism = nchan_ism;
@@ -305,10 +419,26 @@ ivas_error ivas_dec_get_format_fx(
             test();
             IF( st_ivas->ini_frame > 0 && NE_16( nchan_ism, st_ivas->nchan_ism ) )
             {
+#ifdef DECODER_FORMAT_SWITCHING
+                IF( isVoipMode )
+                {
+                    st_ivas->restartNeeded = 1;
+                    move16();
+                    return IVAS_ERR_OK;
+                }
+                ELSE
+                {
+#ifdef DEBUGGING
+                    fprintf( stderr, "\nError: Changing the number of ISMs is not supported!\n" );
+#endif
+                    return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong number of objects signalled!" );
+                }
+#else
 #ifdef DEBUGGING
                 fprintf( stderr, "\nError: Changing the number of ISMs is not supported!\n" );
 #endif
                 return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong number of objects signalled!" );
+#endif
             }
 
             st_ivas->nchan_ism = nchan_ism;
@@ -323,10 +453,26 @@ ivas_error ivas_dec_get_format_fx(
             test();
             IF( st_ivas->ini_frame > 0 && NE_16( nchan_ism, st_ivas->nchan_ism ) )
             {
+#ifdef DECODER_FORMAT_SWITCHING
+                IF( isVoipMode )
+                {
+                    st_ivas->restartNeeded = 1;
+                    move16();
+                    return IVAS_ERR_OK;
+                }
+                ELSE
+                {
+#ifdef DEBUGGING
+                    fprintf( stderr, "\nError: Changing the number of ISMs is not supported!\n" );
+#endif
+                    return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong number of objects signalled!" );
+                }
+#else
 #ifdef DEBUGGING
                 fprintf( stderr, "\nError: Changing the number of ISMs is not supported!\n" );
 #endif
                 return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong number of objects signalled!" );
+#endif
             }
 
             st_ivas->nchan_ism = nchan_ism;
@@ -354,10 +500,26 @@ ivas_error ivas_dec_get_format_fx(
             test();
             IF( st_ivas->ini_frame > 0 && NE_16( sba_order, st_ivas->sba_order ) )
             {
+#ifdef DECODER_FORMAT_SWITCHING
+                IF( isVoipMode )
+                {
+                    st_ivas->restartNeeded = 1;
+                    move16();
+                    return IVAS_ERR_OK;
+                }
+                ELSE
+                {
+#ifdef DEBUGGING
+                    fprintf( stderr, "\nError: Changing the SBA order is not supported!\n" );
+#endif
+                    return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong SBA order signalled!" );
+                }
+#else
 #ifdef DEBUGGING
                 fprintf( stderr, "\nError: Changing the SBA order is not supported!\n" );
 #endif
                 return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong SBA order signalled!" );
+#endif
             }
 
             st_ivas->ism_mode = ivas_osba_ism_mode_select( ivas_total_brate, st_ivas->nchan_ism );
@@ -384,10 +546,26 @@ ivas_error ivas_dec_get_format_fx(
             test();
             IF( st_ivas->ini_frame > 0 && NE_32( st_ivas->transport_config, signaled_config ) )
             {
+#ifdef DECODER_FORMAT_SWITCHING
+                IF( isVoipMode )
+                {
+                    st_ivas->restartNeeded = 1;
+                    move16();
+                    return IVAS_ERR_OK;
+                }
+                ELSE
+                {
+#ifdef DEBUGGING
+                    fprintf( stderr, "\nError: Switching of MC configurations is not supported!\n" );
+#endif
+                    return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "wrong MC configuration signalled!" );
+                }
+#else
 #ifdef DEBUGGING
                 fprintf( stderr, "\nError: Switching of MC configurations is not supported!\n" );
 #endif
                 return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "wrong MC configuration signalled!" );
+#endif
             }
 
             st_ivas->mc_mode = ivas_mc_mode_select_fx( ivas_mc_map_output_config_to_mc_ls_setup_fx( signaled_config ), ivas_total_brate );
@@ -486,10 +664,26 @@ ivas_error ivas_dec_get_format_fx(
             test();
             IF( st_ivas->ini_frame > 0 && NE_16( nchan_ism, st_ivas->nchan_ism ) )
             {
+#ifdef DECODER_FORMAT_SWITCHING
+                IF( isVoipMode )
+                {
+                    st_ivas->restartNeeded = 1;
+                    move16();
+                    return IVAS_ERR_OK;
+                }
+                ELSE
+                {
+#ifdef DEBUGGING
+                    fprintf( stderr, "\nError: Changing the number of ISMs is not supported!\n" );
+#endif
+                    return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong number of objects signalled!" );
+                }
+#else
 #ifdef DEBUGGING
                 fprintf( stderr, "\nError: Changing the number of ISMs is not supported!\n" );
 #endif
                 return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "Wrong number of objects signalled!" );
+#endif
             }
 
             st_ivas->nchan_ism = nchan_ism;
diff --git a/lib_dec/ivas_stat_dec.h b/lib_dec/ivas_stat_dec.h
index 8a384809d0ac1a330084897cf8c25ffbdc037c29..df8607cb5fbbdb9ecc2cc3d86569b65200e6956e 100644
--- a/lib_dec/ivas_stat_dec.h
+++ b/lib_dec/ivas_stat_dec.h
@@ -1223,6 +1223,9 @@ typedef struct Decoder_Struct
 #ifdef TMP_1342_WORKAROUND_DEC_FLUSH_BROKEN_IN_SR
     Word16 flushing;
 #endif
+#ifdef DECODER_FORMAT_SWITCHING
+    UWord8 restartNeeded;                                      /* Flag to check if the decoder requires a restart */
+#endif
 
 } Decoder_Struct;
 
diff --git a/lib_dec/lib_dec.h b/lib_dec/lib_dec.h
index dad682f73d7a61fc5ef6d75bfef2581e8ad8ae44..23a353ff03d4bb4540660bf736528d2c36b2d600 100644
--- a/lib_dec/lib_dec.h
+++ b/lib_dec/lib_dec.h
@@ -341,6 +341,12 @@ ivas_error IVAS_DEC_Flush(
     Word16 *nSamplesFlushed                                 /* o  : number of samples flushed                                               */
 );
 
+#ifdef DECODER_FORMAT_SWITCHING
+bool IVAS_DEC_isRestartNeeded(
+    IVAS_DEC_HANDLE hIvasDec                    /* i/o: IVAS decoder handle                                                      */
+);
+
+#endif
 /* Setter functions - apply changes to decoder configuration */
 
 /*! r: error code */
diff --git a/lib_dec/lib_dec_fx.c b/lib_dec/lib_dec_fx.c
index 5ae845a46b623f1cbb36a084f067e4566e28fa2c..246fd4e297ff23a12bd73c3161dee26f8ccf30cc 100644
--- a/lib_dec/lib_dec_fx.c
+++ b/lib_dec/lib_dec_fx.c
@@ -241,6 +241,11 @@ ivas_error IVAS_DEC_Open(
     /* initialize pointers to handles to NULL */
     ivas_initialize_handles_dec( st_ivas );
 
+#ifdef DECODER_FORMAT_SWITCHING
+    st_ivas->restartNeeded = 0;
+    move16();
+#endif
+
     /* set high-level parameters */
     IF( EQ_16( mode, IVAS_DEC_MODE_EVS ) )
     {
@@ -2159,12 +2164,24 @@ ivas_error IVAS_DEC_GetFormat(
     }
     move32();
 
+#ifdef DECODER_FORMAT_SWITCHING
+    test();
+    IF( EQ_32( *format, IVAS_DEC_BS_MASA ) && hIvasDec->st_ivas->hMasa != NULL )
+    {
+        IF( EQ_32( hIvasDec->st_ivas->hMasa->config.input_ivas_format, MASA_ISM_FORMAT ) )
+        {
+            *format = IVAS_DEC_BS_MASA_ISM;
+            move32();
+        }
+    }
+#else
     test();
     if ( EQ_32( *format, IVAS_DEC_BS_MASA ) && EQ_32( hIvasDec->st_ivas->hMasa->config.input_ivas_format, MASA_ISM_FORMAT ) )
     {
         *format = IVAS_DEC_BS_MASA_ISM;
         move32();
     }
+#endif
 
     return IVAS_ERR_OK;
 }
@@ -3977,7 +3994,9 @@ ivas_error IVAS_DEC_ReadFormat(
 {
     ivas_error error;
     Decoder_Struct *st_ivas;
+#ifndef DECODER_FORMAT_SWITCHING
     IVAS_FORMAT ivas_format_old;
+#endif
     ISM_MODE ism_mode_old;
     MC_MODE mc_mode_old;
     Word16 nchan_transport_old;
@@ -3991,7 +4010,9 @@ ivas_error IVAS_DEC_ReadFormat(
     }
 
     st_ivas = hIvasDec->st_ivas;
+#ifndef DECODER_FORMAT_SWITCHING
     ivas_format_old = st_ivas->ivas_format;
+#endif
     ism_mode_old = st_ivas->ism_mode;
     mc_mode_old = st_ivas->mc_mode;
     nchan_transport_old = st_ivas->nchan_transport;
@@ -4000,7 +4021,9 @@ ivas_error IVAS_DEC_ReadFormat(
     renderer_type_old = st_ivas->renderer_type;
     renderer_type_sec_old = ivas_renderer_secondary_select_fx( st_ivas );
     move32();
+#ifndef DECODER_FORMAT_SWITCHING
     move32();
+#endif
     move32();
     move16();
     move32();
@@ -4018,11 +4041,22 @@ ivas_error IVAS_DEC_ReadFormat(
 
     IF( st_ivas->bfi == 0 )
     {
+#ifdef DECODER_FORMAT_SWITCHING
+        IF( NE_32( error = ivas_dec_get_format_fx( st_ivas, hIvasDec->hVoIP != NULL ), IVAS_ERR_OK ) )
+#else
         IF( NE_32( error = ivas_dec_get_format_fx( st_ivas ), IVAS_ERR_OK ) )
+#endif
         {
             return error;
         }
 
+#ifdef DECODER_FORMAT_SWITCHING
+        IF( st_ivas->restartNeeded > 0 )
+        {
+            return IVAS_ERR_OK;
+        }
+#else
+
         test();
         test();
         test();
@@ -4030,6 +4064,7 @@ ivas_error IVAS_DEC_ReadFormat(
         {
             return ( IVAS_ERROR( IVAS_ERR_INVALID_INPUT_FORMAT, "IVAS format switching is not allowed." ) );
         }
+#endif
 
         /* Select binaural renderer */
         ivas_renderer_select( st_ivas );
@@ -5612,6 +5647,22 @@ ivas_error IVAS_DEC_Flush(
 }
 
 
+#ifdef DECODER_FORMAT_SWITCHING
+/*---------------------------------------------------------------------*
+ * IVAS_DEC_isRestartNeeded( )
+ *
+ *
+ *---------------------------------------------------------------------*/
+
+bool IVAS_DEC_isRestartNeeded(
+    IVAS_DEC_HANDLE hIvasDec /* i/o: IVAS decoder handle                                                      */
+)
+{
+    return hIvasDec->st_ivas->restartNeeded > 0;
+}
+
+
+#endif
 /*---------------------------------------------------------------------*
  * IVAS_DEC_VoIP_IsEmpty( )
  *