diff --git a/acinclude.m4 b/acinclude.m4
index b64b2a7..5662e5a 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -2,7 +2,6 @@ AC_DEFUN([TUXBOX_APPS],[
 AM_CONFIG_HEADER(config.h)
 AM_MAINTAINER_MODE
 
-AC_GNU_SOURCE
 AC_SYS_LARGEFILE
 
 AC_ARG_WITH(target,
@@ -58,21 +57,33 @@ check_path () {
 
 ])
 
+dnl expand nested ${foo}/bar
+AC_DEFUN([TUXBOX_EXPAND_VARIABLE],[__$1="$2"
+	for __CNT in false false false false true; do dnl max 5 levels of indirection
+
+		$1=`eval echo "$__$1"`
+		echo ${$1} | grep -q '\$' || break # 'grep -q' is POSIX, exit if no $ in variable
+		__$1="${$1}"
+	done
+	$__CNT && AC_MSG_ERROR([can't expand variable $1=$2]) dnl bail out if we did not expand
+])
+
 AC_DEFUN([TUXBOX_APPS_DIRECTORY_ONE],[
 AC_ARG_WITH($1,[  $6$7 [[PREFIX$4$5]]],[
 	_$2=$withval
 	if test "$TARGET" = "cdk"; then
-		$2=`eval echo "${targetprefix}$withval"`
+		$2=`eval echo "${targetprefix}$withval"` # no indirection possible IMNSHO
 	else
 		$2=$withval
 	fi
 	TARGET_$2=${$2}
 ],[
-	$2="\${$3}$5"
+	# RFC 1925: "you can always add another level of indirection..."
+	TUXBOX_EXPAND_VARIABLE($2,"${$3}$5")
 	if test "$TARGET" = "cdk"; then
-		_$2=`eval echo "${target$3}$5"`
+		TUXBOX_EXPAND_VARIABLE(_$2,"${target$3}$5")
 	else
-		_$2=`eval echo "${$3}$5"`
+		_$2=${$2}
 	fi
 	TARGET_$2=$_$2
 ])
diff --git a/azbox/dmx_lib.h b/azbox/dmx_lib.h
index ed38048..754511e 100644
--- a/azbox/dmx_lib.h
+++ b/azbox/dmx_lib.h
@@ -8,6 +8,8 @@
 #include <linux/dvb/dmx.h>
 #include "../common/cs_types.h"
 
+#define MAX_DMX_UNITS 4
+
 typedef enum
 {
 	DMX_INVALID = 0,
diff --git a/configure.ac b/configure.ac
index db9cf86..b8a2911 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,6 +2,7 @@ AC_INIT(libstb-hal,0.1.1)
 AM_INIT_AUTOMAKE(libstb-hal,0.1.1)
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES])
 AC_CONFIG_MACRO_DIR([m4])
+AC_GNU_SOURCE
 LT_INIT
 
 ## ugly, disables shared library build (not wanted yet)
diff --git a/generic-pc/audio.cpp b/generic-pc/audio.cpp
index bb814e7..99effcd 100644
--- a/generic-pc/audio.cpp
+++ b/generic-pc/audio.cpp
@@ -45,12 +45,18 @@ extern cDemux *audioDemux;
 static uint8_t *dmxbuf = NULL;
 static int bufpos;
 
+extern bool HAL_nodec;
+
 static cAudio *gThiz = NULL;
 
+static ao_device *adevice = NULL;
+static ao_sample_format sformat;
+
 cAudio::cAudio(void *, void *, void *)
 {
 	thread_started = false;
-	dmxbuf = (uint8_t *)malloc(DMX_BUF_SZ);
+	if (!HAL_nodec)
+		dmxbuf = (uint8_t *)malloc(DMX_BUF_SZ);
 	bufpos = 0;
 	curr_pts = 0;
 	gThiz = this;
@@ -61,6 +67,9 @@ cAudio::~cAudio(void)
 {
 	closeDevice();
 	free(dmxbuf);
+	if (adevice)
+		ao_close(adevice);
+	adevice = NULL;
 	ao_shutdown();
 }
 
@@ -89,7 +98,8 @@ int cAudio::setVolume(unsigned int left, unsigned int right)
 int cAudio::Start(void)
 {
 	lt_info("%s >\n", __func__);
-	OpenThreads::Thread::start();
+	if (! HAL_nodec)
+		OpenThreads::Thread::start();
 	lt_info("%s <\n", __func__);
 	return 0;
 }
@@ -126,21 +136,56 @@ int cAudio::setChannel(int /*channel*/)
 	return 0;
 };
 
-int cAudio::PrepareClipPlay(int ch, int srate, int bits, int little_endian)
+int cAudio::PrepareClipPlay(int ch, int srate, int bits, int le)
 {
-	lt_debug("%s ch %d srate %d bits %d le %d\n", __func__, ch, srate, bits, little_endian);
+	lt_debug("%s ch %d srate %d bits %d le %d adevice %p\n", __func__, ch, srate, bits, le, adevice);;
+	int driver;
+	int byte_format = le ? AO_FMT_LITTLE : AO_FMT_BIG;
+	if (sformat.bits != bits || sformat.channels != ch || sformat.rate != srate ||
+	    sformat.byte_format != byte_format || adevice == NULL)
+	{
+		driver = ao_default_driver_id();
+		sformat.bits = bits;
+		sformat.channels = ch;
+		sformat.rate = srate;
+		sformat.byte_format = byte_format;
+		sformat.matrix = 0;
+		if (adevice)
+			ao_close(adevice);
+		adevice = ao_open_live(driver, &sformat, NULL);
+		ao_info *ai = ao_driver_info(driver);
+		lt_info("%s: changed params ch %d srate %d bits %d le %d adevice %p\n",
+			__func__, ch, srate, bits, le, adevice);;
+		lt_info("libao driver: %d name '%s' short '%s' author '%s'\n",
+				driver, ai->name, ai->short_name, ai->author);
+	}
 	return 0;
 };
 
-int cAudio::WriteClip(unsigned char * /*buffer*/, int /*size*/)
+int cAudio::WriteClip(unsigned char *buffer, int size)
 {
-	lt_debug("cAudio::%s\n", __func__);
-	return 0;
+	lt_debug("cAudio::%s buf 0x%p size %d\n", __func__, buffer, size);
+	if (!adevice) {
+		lt_info("%s: adevice not opened?\n", __func__);
+		return 0;
+	}
+	ao_play(adevice, (char *)buffer, size);
+	return size;
 };
 
 int cAudio::StopClip()
 {
 	lt_debug("%s\n", __func__);
+#if 0
+	/* don't do anything - closing / reopening ao all the time makes for long delays
+	 * reinit on-demand (e.g. for changed parameters) instead */
+	if (!adevice) {
+		lt_info("%s: adevice not opened?\n", __func__);
+		return 0;
+	}
+	ao_close(adevice);
+	adevice = NULL;
+#endif
 	return 0;
 };
 
@@ -232,8 +277,8 @@ void cAudio::run()
 	int ret, driver;
 	/* libao */
 	ao_info *ai;
-	ao_device *adevice;
-	ao_sample_format sformat;
+	// ao_device *adevice;
+	// ao_sample_format sformat;
 
 	curr_pts = 0;
 	av_init_packet(&avpkt);
@@ -279,16 +324,24 @@ void cAudio::run()
 		lt_info("%s: avcodec_alloc_frame failed\n", __func__);
 		goto out2;
 	}
-	driver = ao_default_driver_id();
-	sformat.bits = 16;
-	sformat.channels = c->channels;
-	sformat.rate = c->sample_rate;
-	sformat.byte_format = AO_FMT_NATIVE;
-	sformat.matrix = 0;
-	adevice = ao_open_live(driver, &sformat, NULL);
-	ai = ao_driver_info(driver);
-	lt_info("libao driver: %d name '%s' short '%s' author '%s'\n",
-			driver, ai->name, ai->short_name, ai->author);
+	if (sformat.channels != c->channels || sformat.rate != c->sample_rate ||
+	    sformat.byte_format != AO_FMT_NATIVE || sformat.bits != 16 || adevice == NULL)
+	{
+		driver = ao_default_driver_id();
+		sformat.bits = 16;
+		sformat.channels = c->channels;
+		sformat.rate = c->sample_rate;
+		sformat.byte_format = AO_FMT_NATIVE;
+		sformat.matrix = 0;
+		if (adevice)
+			ao_close(adevice);
+		adevice = ao_open_live(driver, &sformat, NULL);
+		ai = ao_driver_info(driver);
+		lt_info("%s: changed params ch %d srate %d bits %d adevice %p\n",
+			__func__, c->channels, c->sample_rate, 16, adevice);;
+		lt_info("libao driver: %d name '%s' short '%s' author '%s'\n",
+				driver, ai->name, ai->short_name, ai->author);
+	}
 #if 0
 	lt_info(" driver options:");
 	for (int i = 0; i < ai->option_count; ++i)
@@ -309,7 +362,7 @@ void cAudio::run()
 		}
 		av_free_packet(&avpkt);
 	}
-	ao_close(adevice); /* can take long :-( */
+	// ao_close(adevice); /* can take long :-( */
 	avcodec_free_frame(&frame);
  out2:
 	avcodec_close(c);
diff --git a/generic-pc/dmx.cpp b/generic-pc/dmx.cpp
index e771986..19d8fc4 100644
--- a/generic-pc/dmx.cpp
+++ b/generic-pc/dmx.cpp
@@ -76,6 +76,8 @@ static const char *devname[] = {
 static int dmx_tp_count = 0;
 #define MAX_TS_COUNT 8
 
+extern bool HAL_nodec;
+
 cDemux::cDemux(int n)
 {
 	if (n < 0 || n > 2)
@@ -379,14 +381,20 @@ bool cDemux::pesFilter(const unsigned short pid)
 	switch (dmx_type) {
 	case DMX_PCR_ONLY_CHANNEL:
 		p_flt.pes_type = DMX_PES_PCR;
+		if (HAL_nodec)
+			return true;
 		break;
 	case DMX_AUDIO_CHANNEL:
 		p_flt.pes_type = DMX_PES_OTHER;
 		p_flt.output  = DMX_OUT_TSDEMUX_TAP;
+		if (HAL_nodec)	/* no need to demux if we don't decode... */
+			return true;
 		break;
 	case DMX_VIDEO_CHANNEL:
 		p_flt.pes_type = DMX_PES_OTHER;
 		p_flt.output  = DMX_OUT_TSDEMUX_TAP;
+		if (HAL_nodec)
+			return true;
 		break;
 	case DMX_PES_CHANNEL:
 		p_flt.pes_type = DMX_PES_OTHER;
diff --git a/generic-pc/dmx_lib.h b/generic-pc/dmx_lib.h
index ed38048..754511e 100644
--- a/generic-pc/dmx_lib.h
+++ b/generic-pc/dmx_lib.h
@@ -8,6 +8,8 @@
 #include <linux/dvb/dmx.h>
 #include "../common/cs_types.h"
 
+#define MAX_DMX_UNITS 4
+
 typedef enum
 {
 	DMX_INVALID = 0,
diff --git a/generic-pc/init.cpp b/generic-pc/init.cpp
index ad272f9..5fadc88 100644
--- a/generic-pc/init.cpp
+++ b/generic-pc/init.cpp
@@ -9,6 +9,7 @@
 
 static bool initialized = false;
 GLFramebuffer *glfb = NULL;
+bool HAL_nodec = false;
 
 void init_td_api()
 {
@@ -35,6 +36,10 @@ void init_td_api()
 
 		glfb = new GLFramebuffer(x, y); /* hard coded to PAL resolution for now */
 	}
+	/* allow disabling of Audio/video decoders in case we just want to
+	 * valgrind-check other parts... export HAL_NOAVDEC=1 */
+	if (getenv("HAL_NOAVDEC"))
+		HAL_nodec = true;
 	initialized = true;
 }
 
diff --git a/generic-pc/video.cpp b/generic-pc/video.cpp
index 429c3d9..bcce38a 100644
--- a/generic-pc/video.cpp
+++ b/generic-pc/video.cpp
@@ -50,6 +50,8 @@ extern cDemux *videoDemux;
 extern GLFramebuffer *glfb;
 int system_rev = 0;
 
+extern bool HAL_nodec;
+
 static uint8_t *dmxbuf;
 static int bufpos;
 
@@ -66,7 +68,8 @@ cVideo::cVideo(int, void *, void *)
 {
 	lt_debug("%s\n", __func__);
 	av_register_all();
-	dmxbuf = (uint8_t *)malloc(DMX_BUF_SZ);
+	if (!HAL_nodec)
+		dmxbuf = (uint8_t *)malloc(DMX_BUF_SZ);
 	bufpos = 0;
 	thread_running = false;
 	w_h_changed = false;
@@ -135,7 +138,7 @@ int cVideo::setCroppingMode(int)
 int cVideo::Start(void *, unsigned short, unsigned short, void *)
 {
 	lt_info("%s running %d >\n", __func__, thread_running);
-	if (!thread_running)
+	if (!thread_running && !HAL_nodec)
 		OpenThreads::Thread::start();
 	lt_info("%s running %d <\n", __func__, thread_running);
 	return 0;
@@ -206,8 +209,106 @@ void cVideo::SetVideoMode(analog_mode_t)
 {
 }
 
-void cVideo::ShowPicture(const char *)
+void cVideo::ShowPicture(const char *fname)
 {
+	lt_info("%s(%s)\n", __func__, fname);
+	if (access(fname, R_OK))
+		return;
+
+	unsigned int i;
+	int stream_id = -1;
+	int got_frame = 0;
+	int len;
+	AVFormatContext *avfc = NULL;
+	AVCodecContext *c = NULL;
+	AVCodec *codec;
+	AVFrame *frame, *rgbframe;
+	AVPacket avpkt;
+
+	if (avformat_open_input(&avfc, fname, NULL, NULL) < 0) {
+		lt_info("%s: Could not open file %s\n", __func__, fname);
+		return;
+	}
+
+	if (avformat_find_stream_info(avfc, NULL) < 0) {
+		lt_info("%s: Could not find file info %s\n", __func__, fname);
+		goto out_close;
+	}
+	for (i = 0; i < avfc->nb_streams; i++) {
+		if (avfc->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
+			stream_id = i;
+			break;
+		}
+	}
+	if (stream_id < 0)
+		goto out_close;
+	c = avfc->streams[stream_id]->codec;
+	codec = avcodec_find_decoder(c->codec_id);
+	if (!avcodec_open2(c, codec, NULL) < 0) {
+		lt_info("%s: Could not find/open the codec, id 0x%x\n", __func__, c->codec_id);
+		goto out_close;
+	}
+	frame = avcodec_alloc_frame();
+	rgbframe = avcodec_alloc_frame();
+	if (!frame || !rgbframe) {
+		lt_info("%s: Could not allocate video frame\n", __func__);
+		goto out_free;
+	}
+	av_init_packet(&avpkt);
+	if (av_read_frame(avfc, &avpkt) < 0) {
+		lt_info("%s: av_read_frame < 0\n", __func__);
+		goto out_free;
+	}
+	len = avcodec_decode_video2(c, frame, &got_frame, &avpkt);
+	if (len < 0) {
+		lt_info("%s: avcodec_decode_video2 %d\n", __func__, len);
+		av_free_packet(&avpkt);
+		goto out_free;
+	}
+	if (avpkt.size > len)
+		lt_info("%s: WARN: pkt->size %d != len %d\n", __func__, avpkt.size, len);
+	if (got_frame) {
+		unsigned int need = avpicture_get_size(PIX_FMT_RGB32, c->width, c->height);
+		struct SwsContext *convert = sws_getContext(c->width, c->height, c->pix_fmt,
+							    c->width, c->height, PIX_FMT_RGB32,
+							    SWS_BICUBIC, 0, 0, 0);
+		if (!convert)
+			lt_info("%s: ERROR setting up SWS context\n", __func__);
+		else {
+			buf_m.lock();
+			SWFramebuffer *f = &buffers[buf_in];
+			if (f->size() < need)
+				f->resize(need);
+			avpicture_fill((AVPicture *)rgbframe, &(*f)[0], PIX_FMT_RGB32,
+					c->width, c->height);
+			sws_scale(convert, frame->data, frame->linesize, 0, c->height,
+					rgbframe->data, rgbframe->linesize);
+			sws_freeContext(convert);
+			f->width(c->width);
+			f->height(c->height);
+			f->pts(AV_NOPTS_VALUE);
+			AVRational a = av_guess_sample_aspect_ratio(avfc, avfc->streams[stream_id], frame);
+			f->AR(a);
+			buf_in++;
+			buf_in %= VDEC_MAXBUFS;
+			buf_num++;
+			if (buf_num > (VDEC_MAXBUFS - 1)) {
+				lt_info("%s: buf_num overflow\n", __func__);
+				buf_out++;
+				buf_out %= VDEC_MAXBUFS;
+				buf_num--;
+			}
+			buf_m.unlock();
+		}
+	}
+	av_free_packet(&avpkt);
+ out_free:
+	avcodec_close(c);
+	avcodec_free_frame(&frame);
+	avcodec_free_frame(&rgbframe);
+ out_close:
+	avformat_close_input(&avfc);
+	lt_debug("%s(%s) end\n", __func__, fname);
 }
 
 void cVideo::StopPicture()
diff --git a/libspark/dmx_lib.h b/libspark/dmx_lib.h
index e85dc3c..af87a02 100644
--- a/libspark/dmx_lib.h
+++ b/libspark/dmx_lib.h
@@ -8,6 +8,8 @@
 #include <linux/dvb/dmx.h>
 #include "../common/cs_types.h"
 
+#define MAX_DMX_UNITS 4
+
 typedef enum
 {
 	DMX_INVALID = 0,
diff --git a/libtriple/dmx_td.h b/libtriple/dmx_td.h
index e657592..a253f3c 100644
--- a/libtriple/dmx_td.h
+++ b/libtriple/dmx_td.h
@@ -14,6 +14,8 @@ extern "C" {
 #endif
 #define DMX_FILTER_SIZE FILTER_LENGTH
 
+#define MAX_DMX_UNITS 4
+
 typedef enum
 {
 	DMX_INVALID = 0,