Re: [Qemu-devel] [PATCH 1/9] add pflib: PixelFormat conversion library.

[Anthony Liguori <anthony@codemonkey.ws>]

On 08/19/2010 07:40 AM, Gerd Hoffmann wrote:
> Signed-off-by: Gerd Hoffmann<kraxel@redhat.com>
>    

This code is more or less stand alone so it's a good candidate for 
having some in-tree unit tests.

I can provide some examples of how it should be done if you like, but 
just something that lives in tests/ that exercises the functionality and 
can be run under valgrind to verify that we aren't leaking memory.

Using libcheck is also reasonable (take a look at the various check-q* 
in the top level).

Regards,

Anthony Liguori

> ---
>   Makefile.objs |    1 +
>   pflib.c       |  213 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>   pflib.h       |   20 ++++++
>   3 files changed, 234 insertions(+), 0 deletions(-)
>   create mode 100644 pflib.c
>   create mode 100644 pflib.h
>
> diff --git a/Makefile.objs b/Makefile.objs
> index 4a1eaa1..edfca87 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -83,6 +83,7 @@ common-obj-y += qemu-char.o savevm.o #aio.o
>   common-obj-y += msmouse.o ps2.o
>   common-obj-y += qdev.o qdev-properties.o
>   common-obj-y += block-migration.o
> +common-obj-y += pflib.o
>
>   common-obj-$(CONFIG_BRLAPI) += baum.o
>   common-obj-$(CONFIG_POSIX) += migration-exec.o migration-unix.o migration-fd.o
> diff --git a/pflib.c b/pflib.c
> new file mode 100644
> index 0000000..1154d0c
> --- /dev/null
> +++ b/pflib.c
> @@ -0,0 +1,213 @@
> +/*
> + * PixelFormat conversion library.
> + *
> + * Author: Gerd Hoffmann<kraxel@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.  See
> + * the COPYING file in the top-level directory.
> + *
> + */
> +#include "qemu-common.h"
> +#include "console.h"
> +#include "pflib.h"
> +
> +typedef struct QemuPixel QemuPixel;
> +
> +typedef void (*pf_convert)(QemuPfConv *conv,
> +                           void *dst, void *src, uint32_t cnt);
> +typedef void (*pf_convert_from)(PixelFormat *pf,
> +                                QemuPixel *dst, void *src, uint32_t cnt);
> +typedef void (*pf_convert_to)(PixelFormat *pf,
> +                              void *dst, QemuPixel *src, uint32_t cnt);
> +
> +struct QemuPfConv {
> +    pf_convert        convert;
> +    PixelFormat       src;
> +    PixelFormat       dst;
> +
> +    /* for copy_generic() */
> +    pf_convert_from   conv_from;
> +    pf_convert_to     conv_to;
> +    QemuPixel         *conv_buf;
> +    uint32_t          conv_cnt;
> +};
> +
> +struct QemuPixel {
> +    uint8_t red;
> +    uint8_t green;
> +    uint8_t blue;
> +    uint8_t alpha;
> +};
> +
> +/* ----------------------------------------------------------------------- */
> +/* PixelFormat ->  QemuPixel conversions                                    */
> +
> +static void conv_16_to_pixel(PixelFormat *pf,
> +                             QemuPixel *dst, void *src, uint32_t cnt)
> +{
> +    uint16_t *src16 = src;
> +
> +    while (cnt>  0) {
> +        dst->red   = ((*src16&  pf->rmask)>>  pf->rshift)<<  (8 - pf->rbits);
> +        dst->green = ((*src16&  pf->gmask)>>  pf->gshift)<<  (8 - pf->gbits);
> +        dst->blue  = ((*src16&  pf->bmask)>>  pf->bshift)<<  (8 - pf->bbits);
> +        dst->alpha = ((*src16&  pf->amask)>>  pf->ashift)<<  (8 - pf->abits);
> +        dst++, src16++, cnt--;
> +    }
> +}
> +
> +/* assumes pf->{r,g,b,a}bits == 8 */
> +static void conv_32_to_pixel_fast(PixelFormat *pf,
> +                                  QemuPixel *dst, void *src, uint32_t cnt)
> +{
> +    uint32_t *src32 = src;
> +
> +    while (cnt>  0) {
> +        dst->red   = (*src32&  pf->rmask)>>  pf->rshift;
> +        dst->green = (*src32&  pf->gmask)>>  pf->gshift;
> +        dst->blue  = (*src32&  pf->bmask)>>  pf->bshift;
> +        dst->alpha = (*src32&  pf->amask)>>  pf->ashift;
> +        dst++, src32++, cnt--;
> +    }
> +}
> +
> +static void conv_32_to_pixel_generic(PixelFormat *pf,
> +                                     QemuPixel *dst, void *src, uint32_t cnt)
> +{
> +    uint32_t *src32 = src;
> +
> +    while (cnt>  0) {
> +        if (pf->rbits<  8) {
> +            dst->red   = ((*src32&  pf->rmask)>>  pf->rshift)<<  (8 - pf->rbits);
> +        } else {
> +            dst->red   = ((*src32&  pf->rmask)>>  pf->rshift)>>  (pf->rbits - 8);
> +        }
> +        if (pf->gbits<  8) {
> +            dst->green = ((*src32&  pf->gmask)>>  pf->gshift)<<  (8 - pf->gbits);
> +        } else {
> +            dst->green = ((*src32&  pf->gmask)>>  pf->gshift)>>  (pf->gbits - 8);
> +        }
> +        if (pf->bbits<  8) {
> +            dst->blue  = ((*src32&  pf->bmask)>>  pf->bshift)<<  (8 - pf->bbits);
> +        } else {
> +            dst->blue  = ((*src32&  pf->bmask)>>  pf->bshift)>>  (pf->bbits - 8);
> +        }
> +        if (pf->abits<  8) {
> +            dst->alpha = ((*src32&  pf->amask)>>  pf->ashift)<<  (8 - pf->abits);
> +        } else {
> +            dst->alpha = ((*src32&  pf->amask)>>  pf->ashift)>>  (pf->abits - 8);
> +        }
> +        dst++, src32++, cnt--;
> +    }
> +}
> +
> +/* ----------------------------------------------------------------------- */
> +/* QemuPixel ->  PixelFormat conversions                                    */
> +
> +static void conv_pixel_to_16(PixelFormat *pf,
> +                             void *dst, QemuPixel *src, uint32_t cnt)
> +{
> +    uint16_t *dst16 = dst;
> +
> +    while (cnt>  0) {
> +        *dst16  = ((uint16_t)src->red>>  (8 - pf->rbits))<<  pf->rshift;
> +        *dst16 |= ((uint16_t)src->green>>  (8 - pf->gbits))<<  pf->gshift;
> +        *dst16 |= ((uint16_t)src->blue>>  (8 - pf->bbits))<<  pf->bshift;
> +        *dst16 |= ((uint16_t)src->alpha>>  (8 - pf->abits))<<  pf->ashift;
> +        dst16++, src++, cnt--;
> +    }
> +}
> +
> +static void conv_pixel_to_32(PixelFormat *pf,
> +                             void *dst, QemuPixel *src, uint32_t cnt)
> +{
> +    uint32_t *dst32 = dst;
> +
> +    while (cnt>  0) {
> +        *dst32  = ((uint32_t)src->red>>  (8 - pf->rbits))<<  pf->rshift;
> +        *dst32 |= ((uint32_t)src->green>>  (8 - pf->gbits))<<  pf->gshift;
> +        *dst32 |= ((uint32_t)src->blue>>  (8 - pf->bbits))<<  pf->bshift;
> +        *dst32 |= ((uint32_t)src->alpha>>  (8 - pf->abits))<<  pf->ashift;
> +        dst32++, src++, cnt--;
> +    }
> +}
> +
> +/* ----------------------------------------------------------------------- */
> +/* PixelFormat ->  PixelFormat conversions                                  */
> +
> +static void convert_copy(QemuPfConv *conv, void *dst, void *src, uint32_t cnt)
> +{
> +    uint32_t bytes = cnt * conv->src.bytes_per_pixel;
> +    memcpy(dst, src, bytes);
> +}
> +
> +static void convert_generic(QemuPfConv *conv, void *dst, void *src, uint32_t cnt)
> +{
> +    if (conv->conv_cnt<  cnt) {
> +        conv->conv_cnt = cnt;
> +        conv->conv_buf = qemu_realloc(conv->conv_buf, sizeof(QemuPixel) * conv->conv_cnt);
> +    }
> +    conv->conv_from(&conv->src, conv->conv_buf, src, cnt);
> +    conv->conv_to(&conv->dst, dst, conv->conv_buf, cnt);
> +}
> +
> +/* ----------------------------------------------------------------------- */
> +/* public interface                                                        */
> +
> +QemuPfConv *qemu_pf_conv_get(PixelFormat *dst, PixelFormat *src)
> +{
> +    QemuPfConv *conv = qemu_mallocz(sizeof(QemuPfConv));
> +
> +    conv->src = *src;
> +    conv->dst = *dst;
> +
> +    if (memcmp(&conv->src,&conv->dst, sizeof(PixelFormat)) == 0) {
> +        /* formats identical, can simply copy */
> +        conv->convert = convert_copy;
> +    } else {
> +        /* generic two-step conversion: src ->  QemuPixel ->  dst  */
> +        switch (conv->src.bytes_per_pixel) {
> +        case 2:
> +            conv->conv_from = conv_16_to_pixel;
> +            break;
> +        case 4:
> +            if (conv->src.rbits == 8&&  conv->src.gbits == 8&&  conv->src.bbits == 8) {
> +                conv->conv_from = conv_32_to_pixel_fast;
> +            } else {
> +                conv->conv_from = conv_32_to_pixel_generic;
> +            }
> +            break;
> +        default:
> +            goto err;
> +        }
> +        switch (conv->dst.bytes_per_pixel) {
> +        case 2:
> +            conv->conv_to = conv_pixel_to_16;
> +            break;
> +        case 4:
> +            conv->conv_to = conv_pixel_to_32;
> +            break;
> +        default:
> +            goto err;
> +        }
> +        conv->convert = convert_generic;
> +    }
> +    return conv;
> +
> +err:
> +    qemu_free(conv);
> +    return NULL;
> +}
> +
> +void qemu_pf_conv_run(QemuPfConv *conv, void *dst, void *src, uint32_t cnt)
> +{
> +    conv->convert(conv, dst, src, cnt);
> +}
> +
> +void qemu_pf_conv_put(QemuPfConv *conv)
> +{
> +    if (conv) {
> +        qemu_free(conv->conv_buf);
> +        qemu_free(conv);
> +    }
> +}
> diff --git a/pflib.h b/pflib.h
> new file mode 100644
> index 0000000..b70c313
> --- /dev/null
> +++ b/pflib.h
> @@ -0,0 +1,20 @@
> +#ifndef __QEMU_PFLIB_H
> +#define __QEMU_PFLIB_H
> +
> +/*
> + * PixelFormat conversion library.
> + *
> + * Author: Gerd Hoffmann<kraxel@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.  See
> + * the COPYING file in the top-level directory.
> + *
> + */
> +
> +typedef struct QemuPfConv QemuPfConv;
> +
> +QemuPfConv *qemu_pf_conv_get(PixelFormat *dst, PixelFormat *src);
> +void qemu_pf_conv_run(QemuPfConv *conv, void *dst, void *src, uint32_t cnt);
> +void qemu_pf_conv_put(QemuPfConv *conv);
> +
> +#endif
>