[FFmpeg-devel] [PATCH] brender_pix: a new image decoder

Paul B Mahol onemda at gmail.com
Thu Nov 15 17:03:01 CET 2012


On 11/14/12, Aleksi Nurmi <aleksi.nurmi at gmail.com> wrote:
> PIX is an image file format that was used by the BRender 3d engine.
>
> Signed-off-by: Aleksi Nurmi <aleksi.nurmi at gmail.com>
> ---
>  Changelog                |    1 +
>  doc/general.texi         |    2 +
>  libavcodec/Makefile      |    1 +
>  libavcodec/allcodecs.c   |    1 +
>  libavcodec/avcodec.h     |    1 +
>  libavcodec/brender_pix.c |  244
> ++++++++++++++++++++++++++++++++++++++++++++++
>  libavcodec/codec_desc.c  |    6 ++
>  libavcodec/version.h     |    2 +-
>  libavformat/img2.c       |    1 +
>  9 files changed, 258 insertions(+), 1 deletion(-)
>  create mode 100644 libavcodec/brender_pix.c
>
> diff --git a/Changelog b/Changelog
> index 9ef12b8..e274478 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -23,6 +23,7 @@ version <next>:
>  - field filter ported from libmpcodecs
>  - AVR demuxer
>  - geq filter ported from libmpcodecs
> +- BRender PIX image decoder
>
>
>  version 1.0:
> diff --git a/doc/general.texi b/doc/general.texi
> index 9768339..368a472 100644
> --- a/doc/general.texi
> +++ b/doc/general.texi
> @@ -407,6 +407,8 @@ following image formats are supported:
>      @tab Only uncompressed GIFs are generated.
>  @item BMP          @tab X @tab X
>      @tab Microsoft BMP image
> + at item PIX          @tab   @tab X
> +    @tab PIX is an image format used in the Argonaut BRender engine.
>  @item DPX          @tab X @tab X
>      @tab Digital Picture Exchange
>  @item EXR          @tab   @tab X
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 5f8776d..7b6bb31 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -135,6 +135,7 @@ OBJS-$(CONFIG_BMP_DECODER)             += bmp.o
> msrledec.o
>  OBJS-$(CONFIG_BMP_ENCODER)             += bmpenc.o
>  OBJS-$(CONFIG_BMV_VIDEO_DECODER)       += bmv.o
>  OBJS-$(CONFIG_BMV_AUDIO_DECODER)       += bmv.o
> +OBJS-$(CONFIG_BRENDER_PIX_DECODER)     += brender_pix.o
>  OBJS-$(CONFIG_C93_DECODER)             += c93.o
>  OBJS-$(CONFIG_CAVS_DECODER)            += cavs.o cavsdec.o cavsdsp.o \
>                                            cavsdata.o mpeg12data.o
> diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
> index 6bad573..947b201 100644
> --- a/libavcodec/allcodecs.c
> +++ b/libavcodec/allcodecs.c
> @@ -90,6 +90,7 @@ void avcodec_register_all(void)
>      REGISTER_DECODER (BINK, bink);
>      REGISTER_ENCDEC  (BMP, bmp);
>      REGISTER_DECODER (BMV_VIDEO, bmv_video);
> +    REGISTER_DECODER (BRENDER_PIX, brender_pix);
>      REGISTER_DECODER (C93, c93);
>      REGISTER_DECODER (CAVS, cavs);
>      REGISTER_DECODER (CDGRAPHICS, cdgraphics);
> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
> index 368f2c4..0779597 100644
> --- a/libavcodec/avcodec.h
> +++ b/libavcodec/avcodec.h
> @@ -267,6 +267,7 @@ enum AVCodecID {
>      AV_CODEC_ID_MTS2,
>      AV_CODEC_ID_CLLC,
>      AV_CODEC_ID_MSS2,
> +    AV_CODEC_ID_BRENDER_PIX,
>      AV_CODEC_ID_Y41P       = MKBETAG('Y','4','1','P'),
>      AV_CODEC_ID_ESCAPE130  = MKBETAG('E','1','3','0'),
>      AV_CODEC_ID_EXR        = MKBETAG('0','E','X','R'),
> diff --git a/libavcodec/brender_pix.c b/libavcodec/brender_pix.c
> new file mode 100644
> index 0000000..4527d56
> --- /dev/null
> +++ b/libavcodec/brender_pix.c
> @@ -0,0 +1,244 @@
> +/*
> + * BRender PIX (.pix) image decoder
> + * Copyright (c) 2012 Aleksi Nurmi
> + *
> + * Tested against samples from I-War / Independence War and Defiance.
> + *
> + * Note that there are PAL8 format images that do not contain a palette.
> In
> + * this case, the decoder sets the palette_has_changed property of the
> AVFrame
> + * to 0.

Such text about background story should be in separate comment block
bellow copyright,
> + *
> + * This file is part of Libav.

This is not libav mailing list/project.
> + *
> + * Libav is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * Libav is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with Libav; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
> USA
> + */
> +
> +#include "libavutil/imgutils.h"
> +#include "avcodec.h"
> +#include "bytestream.h"
> +#include "get_bits.h"

unused
> +
> +typedef struct BRPixContext {
> +    AVFrame frame;
> +} BRPixContext;
> +
> +typedef struct BRPixHeader {
> +    int format;
> +    unsigned int width, height;
> +} BRPixHeader;

No much point in separate struct.
> +
> +static av_cold int brpix_init(AVCodecContext *avctx) {

Please follow style of other files and put { in separate line.
> +    BRPixContext *s = avctx->priv_data;
> +
> +    avcodec_get_frame_defaults(&s->frame);
> +    avctx->coded_frame = &s->frame;
> +
> +    return 0;
> +}
> +
> +static int brpix_decode_header(BRPixHeader *out, GetByteContext *pgb) {

ditto
> +    unsigned int header_len = bytestream2_get_be32(pgb);
> +
> +    out->format = bytestream2_get_byte(pgb);
> +    bytestream2_skip(pgb, 2);
> +    out->width = bytestream2_get_be16(pgb);
> +    out->height = bytestream2_get_be16(pgb);
> +
> +    // the header is at least 11 bytes long; we read the first 7
> +    if (header_len < 11) {
> +        return 0;
> +    }
> +
> +    // skip the rest of the header
> +    bytestream2_skip(pgb, header_len-7);
> +
> +    return 1;
> +}
> +
> +static int brpix_decode_frame(AVCodecContext *avctx,
> +                              void *data, int *data_size_out,
> +                              AVPacket *avpkt) {
> +    BRPixContext *s = avctx->priv_data;
> +    AVFrame *frame_out = data;
> +
> +    int ok;
> +    GetByteContext gb;
> +
> +    unsigned int bytes_pp;
> +
> +    unsigned int magic[4];
> +    unsigned int chunk_type;
> +    unsigned int data_len;
> +    BRPixHeader hdr;
> +
> +    bytestream2_init(&gb, avpkt->data, avpkt->size);
> +
> +    magic[0] = bytestream2_get_be32(&gb);
> +    magic[1] = bytestream2_get_be32(&gb);
> +    magic[2] = bytestream2_get_be32(&gb);
> +    magic[3] = bytestream2_get_be32(&gb);
> +
> +    if (magic[0] != 0x12 ||
> +        magic[1] != 0x8 ||
> +        magic[2] != 0x2 ||
> +        magic[3] != 0x2)
> +    {
> +        av_log(avctx, AV_LOG_ERROR, "Not a BRender PIX file\n");
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    chunk_type = bytestream2_get_be32(&gb);
> +    if (chunk_type != 0x3 && chunk_type != 0x3d) {
> +        av_log(avctx, AV_LOG_ERROR, "Invalid chunk type %d\n",
> chunk_type);
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    ok = brpix_decode_header(&hdr, &gb);
> +    if (!ok) {
> +        av_log(avctx, AV_LOG_ERROR, "Invalid header length\n");
> +        return AVERROR_INVALIDDATA;
> +    }
> +    switch (hdr.format) {
> +    case 3:
> +        avctx->pix_fmt = AV_PIX_FMT_PAL8;
> +        bytes_pp = 1;
> +        break;
> +    case 4:
> +        avctx->pix_fmt = AV_PIX_FMT_RGB555BE;
> +        bytes_pp = 2;
> +        break;
> +    case 5:
> +        avctx->pix_fmt = AV_PIX_FMT_RGB565BE;
> +        bytes_pp = 2;
> +        break;
> +    case 6:
> +        avctx->pix_fmt = AV_PIX_FMT_RGB24;
> +        bytes_pp = 3;
> +        break;
> +    case 7:
> +        avctx->pix_fmt = AV_PIX_FMT_0RGB;
> +        bytes_pp = 4;
> +        break;
> +    case 18:
> +        // gray + alpha
> +        avctx->pix_fmt = AV_PIX_FMT_Y400A;
> +        bytes_pp = 2;
> +        break;
> +    default:
> +        av_log(avctx, AV_LOG_ERROR, "PIX format %d is not supported\n",
redundant "PIX"
> +                                    hdr.format);
> +        return AVERROR_PATCHWELCOME;
> +    }
> +
> +    if (s->frame.data[0])
> +        avctx->release_buffer(avctx, &s->frame);
> +
> +    if (av_image_check_size(hdr.width, hdr.height, 0, avctx) < 0)
> +        return AVERROR_INVALIDDATA;
> +
> +    if (hdr.width != avctx->width || hdr.height != avctx->height)
> +        avcodec_set_dimensions(avctx, hdr.width, hdr.height);
> +
> +    if (avctx->get_buffer(avctx, &s->frame) < 0) {
> +        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
> +        return -1;
please return maningful error code (the one returned by get_buffer())

> +    }
> +
> +    chunk_type = bytestream2_get_be32(&gb);
> +
> +    if (avctx->pix_fmt == AV_PIX_FMT_PAL8 &&
> +        (chunk_type == 0x3 || chunk_type == 0x3d))
> +    {
> +        BRPixHeader palhdr;
> +        uint32_t *pal_out = (uint32_t *)s->frame.data[1];
> +
> +        ok = brpix_decode_header(&palhdr, &gb);
> +        if (!ok) {
> +            av_log(avctx, AV_LOG_ERROR, "Invalid palette header
> length\n");
> +            return AVERROR_INVALIDDATA;
> +        }
> +        if (palhdr.format != 7) {
> +            av_log(avctx, AV_LOG_ERROR, "Palette is not in RGBX
> format\n");
> +            return AVERROR_INVALIDDATA;
> +        }
> +
> +        chunk_type = bytestream2_get_be32(&gb);
> +        data_len = bytestream2_get_be32(&gb);
> +        bytestream2_skip(&gb, 8);
> +        if (chunk_type != 0x21 || data_len != 1032 ||
> +            bytestream2_get_bytes_left(&gb) < 1032)
> +        {
> +            av_log(avctx, AV_LOG_ERROR, "Invalid palette data\n");
> +            return AVERROR_INVALIDDATA;
> +        }
> +        // convert 0RGB to machine endian format (ARGB32)
> +        for (int i = 0; i < 256; ++i) {
> +            bytestream2_skipu(&gb, 1);
> +            *pal_out++ = (0xFFU << 24) | bytestream2_get_be24u(&gb);

IMHO overwritting instead of this would be better.
> +        }
> +        bytestream2_skip(&gb, 8);
> +
> +        s->frame.palette_has_changed = 1;
> +
> +        chunk_type = bytestream2_get_be32(&gb);
> +    }
> +
> +    data_len = bytestream2_get_be32(&gb);
> +    bytestream2_skip(&gb, 8);
> +
> +    // read the image data to the buffer
> +    {

Ugly.
> +        unsigned int bytes_per_scanline = bytes_pp * hdr.width;
> +        unsigned int bytes_left = bytestream2_get_bytes_left(&gb);
> +
> +        if (chunk_type != 0x21 || data_len != bytes_left ||
> +            bytes_left / bytes_per_scanline < hdr.height)
> +        {
put { above and after ) .
> +            av_log(avctx, AV_LOG_ERROR, "Invalid image data\n");
> +            return AVERROR_INVALIDDATA;
> +        }
> +
> +        av_image_copy_plane(s->frame.data[0], s->frame.linesize[0],
> +                            avpkt->data + bytestream2_tell(&gb),
> +                            bytes_per_scanline,
> +                            bytes_per_scanline, hdr.height);
> +    }
> +
> +    *frame_out = s->frame;
> +    *data_size_out = sizeof(AVFrame);
> +
> +    return avpkt->size;
> +}
> +
> +static av_cold int brpix_end(AVCodecContext *avctx) {
> +    BRPixContext *s = avctx->priv_data;
> +
> +    if(s->frame.data[0])
> +        avctx->release_buffer(avctx, &s->frame);
> +
> +    return 0;
> +}
> +
> +AVCodec ff_brender_pix_decoder = {
> +    .name           = "brender_pix",
> +    .type           = AVMEDIA_TYPE_VIDEO,
> +    .id             = AV_CODEC_ID_BRENDER_PIX,
> +    .priv_data_size = sizeof(BRPixContext),
> +    .init           = brpix_init,
> +    .close          = brpix_end,
> +    .decode         = brpix_decode_frame,
> +    .capabilities   = CODEC_CAP_DR1,
> +    .long_name      = NULL_IF_CONFIG_SMALL("BRender PIX image"),
> +};
> diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
> index 48dbe06..0330db8 100644
> --- a/libavcodec/codec_desc.c
> +++ b/libavcodec/codec_desc.c
> @@ -1321,6 +1321,12 @@ static const AVCodecDescriptor codec_descriptors[] =
> {
>          .name      = "xface",
>          .long_name = NULL_IF_CONFIG_SMALL("X-face image"),
>      },
> +    {
> +        .id        = AV_CODEC_ID_BRENDER_PIX,
> +        .type      = AVMEDIA_TYPE_VIDEO,
> +        .name      = "brender_pix",
> +        .long_name = NULL_IF_CONFIG_SMALL("BRender PIX image"),
> +    },
>
>      /* various PCM "codecs" */
>      {
> diff --git a/libavcodec/version.h b/libavcodec/version.h
> index ec874f4..006e8f1 100644
> --- a/libavcodec/version.h
> +++ b/libavcodec/version.h
> @@ -29,7 +29,7 @@
>  #include "libavutil/avutil.h"
>
>  #define LIBAVCODEC_VERSION_MAJOR 54
> -#define LIBAVCODEC_VERSION_MINOR 71
> +#define LIBAVCODEC_VERSION_MINOR 72
>  #define LIBAVCODEC_VERSION_MICRO 100
>
>  #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
> diff --git a/libavformat/img2.c b/libavformat/img2.c
> index 3867477..5f2c68b 100644
> --- a/libavformat/img2.c
> +++ b/libavformat/img2.c
> @@ -76,6 +76,7 @@ static const IdStrMap img_tags[] = {
>      { AV_CODEC_ID_XBM       , "xbm"},
>      { AV_CODEC_ID_XFACE     , "xface"},
>      { AV_CODEC_ID_XWD       , "xwd"},
> +    { AV_CODEC_ID_BRENDER_PIX, "pix"},
>      { AV_CODEC_ID_NONE      , NULL}
>  };
>
> --
> 1.7.9.5
>
> _______________________________________________
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> ffmpeg-devel at ffmpeg.org
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>


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