--- a/include/sndfile.h
+++ b/include/sndfile.h
@@ -229,6 +229,9 @@
 	SFC_GET_BITRATE_MODE			= 0x1304,
 	SFC_SET_BITRATE_MODE			= 0x1305,
 
+	/* WebEngine extension: int target bits/s, native Vorbis managed encoding. */
+	SFC_WEB_SET_VORBIS_BITRATE		= 0x7B01,
+
 	/* Cart Chunk support */
 	SFC_SET_CART_INFO				= 0x1400,
 	SFC_GET_CART_INFO				= 0x1401,
--- a/src/ogg_vorbis.c
+++ b/src/ogg_vorbis.c
@@ -137,6 +137,9 @@
 	vorbis_block vblock ;
 	/* Encoding quality in range [0.0, 1.0]. */
 	double quality ;
+	/* WebEngine: zero keeps upstream VBR quality mode. */
+	int nominal_bitrate ;
+	int header_ready ;
 	/* Offset of the first samples' granule position. */
 	uint64_t pcm_start ;
 	/* Last valid samples' granule position. */
@@ -313,20 +316,22 @@
 	VORBIS_PRIVATE *vdata = (VORBIS_PRIVATE *) psf->codec_data ;
 	int k, ret ;
 
+	if (vdata->header_ready)
+		return 0 ;
+
 	vorbis_info_init (&vdata->vinfo) ;
 
-	/* The style of encoding should be selectable here, VBR quality mode. */
-	ret = vorbis_encode_init_vbr (&vdata->vinfo, psf->sf.channels, psf->sf.samplerate, vdata->quality) ;
-
-#if 0
-	ret = vorbis_encode_init (&vdata->vinfo, psf->sf.channels, psf->sf.samplerate, -1, 128000, -1) ; /* average bitrate mode */
-	ret = (	vorbis_encode_setup_managed (&vdata->vinfo, psf->sf.channels, psf->sf.samplerate, -1, 128000, -1)
-			|| vorbis_encode_ctl (&vdata->vinfo, OV_ECTL_RATEMANAGE_AVG, NULL)
-			|| vorbis_encode_setup_init (&vdata->vinfo)
-			) ;
-#endif
+	/* Select libvorbis' original managed average bitrate encoder when requested.
+	** No bitrate-to-quality approximation: the native codec owns rate control. */
+	if (vdata->nominal_bitrate > 0)
+		ret = vorbis_encode_init (&vdata->vinfo, psf->sf.channels, psf->sf.samplerate,
+				-1, vdata->nominal_bitrate, -1) ;
+	else
+		ret = vorbis_encode_init_vbr (&vdata->vinfo, psf->sf.channels, psf->sf.samplerate, vdata->quality) ;
 	if (ret)
+	{	vorbis_info_clear (&vdata->vinfo) ;
 		return SFE_BAD_OPEN_FORMAT ;
+		} ;
 
 	vdata->gp = 0 ;
 
@@ -395,6 +400,7 @@
 			} ;
 	}
 
+	vdata->header_ready = SF_TRUE ;
 	return 0 ;
 } /* vorbis_write_header */
 
@@ -402,6 +408,7 @@
 vorbis_close (SF_PRIVATE *psf)
 {	OGG_PRIVATE* odata = psf->container_data ;
 	VORBIS_PRIVATE *vdata = psf->codec_data ;
+	int error = 0 ;
 
 	if (odata == NULL || vdata == NULL)
 		return 0 ;
@@ -411,8 +418,10 @@
 
 	if (psf->file.mode == SFM_WRITE)
 	{
-		if (psf->write_current <= 0)
-			vorbis_write_header (psf, 0) ;
+		/* A rejected rate/rate-channel combination must never drain an
+		** uninitialized encoder or leak its native allocations on close. */
+		if (! vdata->header_ready && (error = vorbis_write_header (psf, 0)))
+			goto cleanup ;
 
 		vorbis_analysis_wrote (&vdata->vdsp, 0) ;
 		while (vorbis_analysis_blockout (&vdata->vdsp, &vdata->vblock) == 1)
@@ -441,6 +450,7 @@
 		}
 	}
 
+cleanup:
 	/* ogg_page and ogg_packet structs always point to storage in
 	   libvorbis.  They are never freed or manipulated directly */
 
@@ -449,7 +459,7 @@
 	vorbis_comment_clear (&vdata->vcomment) ;
 	vorbis_info_clear (&vdata->vinfo) ;
 
-	return 0 ;
+	return error ;
 } /* vorbis_close */
 
 int
@@ -515,12 +525,36 @@
 	VORBIS_PRIVATE *vdata = (VORBIS_PRIVATE *) psf->codec_data ;
 
 	switch (command)
-	{	case SFC_SET_COMPRESSION_LEVEL :
+	{	case SFC_WEB_SET_VORBIS_BITRATE :
+		{	vorbis_info candidate ;
+			int bitrate, result ;
+			if (psf->file.mode != SFM_WRITE || psf->have_written || vdata->header_ready ||
+				data == NULL || datasize != sizeof (int))
+				return SF_FALSE ;
+			bitrate = *((int *) data) ;
+			if (bitrate <= 0)
+				return SF_FALSE ;
+
+			/* Ask the same encoder to accept the complete rate/channel tuple
+			** before retaining it. A failed command leaves settings unchanged. */
+			vorbis_info_init (&candidate) ;
+			result = vorbis_encode_init (&candidate, psf->sf.channels, psf->sf.samplerate,
+					-1, bitrate, -1) ;
+			vorbis_info_clear (&candidate) ;
+			if (result)
+				return SF_FALSE ;
+			vdata->nominal_bitrate = bitrate ;
+			return SF_TRUE ;
+			} ;
+
+		case SFC_SET_COMPRESSION_LEVEL :
 			if (data == NULL || datasize != sizeof (double))
 				return SF_FALSE ;
 
-			if (psf->have_written)
+			if (psf->file.mode != SFM_WRITE || psf->have_written || vdata->header_ready)
 				return SF_FALSE ;
+
+			vdata->nominal_bitrate = 0 ;
 
 			vdata->quality = 1.0 - *((double *) data) ;