[FFmpeg-devel] [PATCH 1/4] SGI RLE 8-bit decoder

Paul B Mahol onemda at gmail.com
Tue Dec 11 12:04:07 CET 2012


On 12/11/12, Peter Ross <pross at xvid.org> wrote:
> Signed-off-by: Peter Ross <pross at xvid.org>
> ---
>  Changelog               |   1 +
>  doc/general.texi        |   1 +
>  libavcodec/Makefile     |   1 +
>  libavcodec/allcodecs.c  |   1 +
>  libavcodec/avcodec.h    |   1 +
>  libavcodec/codec_desc.c |   7 +++
>  libavcodec/sgirledec.c  | 152
> ++++++++++++++++++++++++++++++++++++++++++++++++
>  7 files changed, 164 insertions(+)
>  create mode 100644 libavcodec/sgirledec.c
>
> diff --git a/Changelog b/Changelog
> index 6be40bb..e8e6911 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -40,6 +40,7 @@ version <next>:
>  - Virtual concatenation demuxer
>  - VobSub demuxer
>  - JSON captions for TED talks decoding support
> +- SGI RLE 8-bit decoder
>
>
>  version 1.0:
> diff --git a/doc/general.texi b/doc/general.texi
> index ed1269f..eb12364 100644
> --- a/doc/general.texi
> +++ b/doc/general.texi
> @@ -664,6 +664,7 @@ following image formats are supported:
>      @tab Texture dictionaries used by the Renderware Engine.
>  @item RL2 video              @tab     @tab  X
>      @tab used in some games by Entertainment Software Partners
> + at item SGI RLE 8-bit          @tab     @tab  X
>  @item Sierra VMD video       @tab     @tab  X
>      @tab Used in Sierra VMD files.
>  @item Smacker video          @tab     @tab  X
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 0507028..9e6edc1 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -376,6 +376,7 @@ OBJS-$(CONFIG_S302M_DECODER)           += s302m.o
>  OBJS-$(CONFIG_SANM_DECODER)            += sanm.o
>  OBJS-$(CONFIG_SGI_DECODER)             += sgidec.o
>  OBJS-$(CONFIG_SGI_ENCODER)             += sgienc.o rle.o
> +OBJS-$(CONFIG_SGIRLE_DECODER)          += sgirledec.o
>  OBJS-$(CONFIG_SHORTEN_DECODER)         += shorten.o
>  OBJS-$(CONFIG_SIPR_DECODER)            += sipr.o acelp_pitch_delay.o \
>                                            celp_math.o acelp_vectors.o \
> diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
> index 4743bb1..5dcd509 100644
> --- a/libavcodec/allcodecs.c
> +++ b/libavcodec/allcodecs.c
> @@ -215,6 +215,7 @@ void avcodec_register_all(void)
>      REGISTER_DECODER (S302M, s302m);
>      REGISTER_DECODER (SANM, sanm);
>      REGISTER_ENCDEC  (SGI, sgi);
> +    REGISTER_DECODER (SGIRLE, sgirle);
>      REGISTER_DECODER (SMACKER, smacker);
>      REGISTER_DECODER (SMC, smc);
>      REGISTER_ENCDEC  (SNOW, snow);
> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
> index e432040..b9317f0 100644
> --- a/libavcodec/avcodec.h
> +++ b/libavcodec/avcodec.h
> @@ -285,6 +285,7 @@ enum AVCodecID {
>      AV_CODEC_ID_AVRN       = MKBETAG('A','V','R','n'),
>      AV_CODEC_ID_CPIA       = MKBETAG('C','P','I','A'),
>      AV_CODEC_ID_XFACE      = MKBETAG('X','F','A','C'),
> +    AV_CODEC_ID_SGIRLE     = MKBETAG('S','G','I','R'),
>
>      /* various PCM "codecs" */
>      AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the
> start of audio codecs
> diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
> index 8e8685c..4ba31e9 100644
> --- a/libavcodec/codec_desc.c
> +++ b/libavcodec/codec_desc.c
> @@ -752,6 +752,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
>          .props     = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY,
>      },
>      {
> +        .id        = AV_CODEC_ID_SGIRLE,
> +        .type      = AVMEDIA_TYPE_VIDEO,
> +        .name      = "sgirle",
> +        .long_name = NULL_IF_CONFIG_SMALL("SGI RLE 8-bit"),
> +        .props     = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSLESS,
> +    },
> +    {
>          .id        = AV_CODEC_ID_C93,
>          .type      = AVMEDIA_TYPE_VIDEO,
>          .name      = "c93",
> diff --git a/libavcodec/sgirledec.c b/libavcodec/sgirledec.c
> new file mode 100644
> index 0000000..cd31e0f
> --- /dev/null
> +++ b/libavcodec/sgirledec.c
> @@ -0,0 +1,152 @@
> +/*
> + * SGI RLE 8-bit decoder
> + * Copyright (c) 2012 Peter Ross
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg 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.
> + *
> + * FFmpeg 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 FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
> USA
> + */
> +
> +/**
> + * @file
> + * SGI RLE 8-bit decoder
> + */
> +
> +#include "libavutil/intreadwrite.h"
> +#include "avcodec.h"
> +#include "bytestream.h"
> +
> +typedef struct {
> +    AVFrame frame;
> +} SgiContext;
> +
> +static av_cold int sgirle_decode_init(AVCodecContext *avctx)
> +{
> +    SgiContext *s = avctx->priv_data;
> +    avctx->pix_fmt = AV_PIX_FMT_BGR8;
> +
> +    avcodec_get_frame_defaults(&s->frame);
> +    s->frame.data[0] = NULL;

Is that line really needed?
Other decoders set avctx->coded_frame
> +    return 0;
> +}
> +
> +/**
> + * Convert SGI RGB332 pixel into PIX_FMT_BGR8
> + * SGI RGB332 is packed RGB 3:3:2, 8bpp, (msb)3R 2B 3G(lsb)
> + */
> +#define RGB332_TO_BGR8(x) (((x << 3) & 0xC0) | ((x << 3) & 0x38) | ((x >>
> 5) & 7))
> +
> +static av_always_inline void memcpy_rgb332_to_bgr8(uint8_t *dst, const
> uint8_t *src, int size)
> +{
> +    int i;
> +    for (i = 0; i < size; i++)
> +        dst[i] = RGB332_TO_BGR8(src[i]);
> +}
> +
> +/**
> + * @param[out] dst Destination buffer
> + * @param[in] src Source buffer
> + * @param src_size Source buffer size (bytes)
> + * @param width Width of destination buffer (pixels)
> + * @param height Height of destination buffer (pixels)
> + * @param linesize Line size of destination buffer (bytes)
> + * @return < 0 on unknown opcode
> + */
> +static int decode_sgirle8(uint8_t *dst, const uint8_t *src, int src_size,
> int width, int height, int linesize)
> +{
> +    const uint8_t *src_end = src + src_size;
> +    int x = 0, y = 0;
> +
> +#define INC_XY(n) \
> +    x += n; \
> +    if (x >= width) { \
> +        y++; \
> +        if (y >= height) \
> +            return 0; \
> +        x = 0; \
> +    }
> +
> +    while (src_end - src >= 2) {
> +        uint8_t v = *src++;
> +        if (v > 0 && v < 0xC0) {
> +            do {
> +                int length = FFMIN(v, width - x);
> +                memset(dst + y*linesize + x, RGB332_TO_BGR8(*src),
> length);
> +                INC_XY(length);
> +                v   -= length;
> +            } while (v > 0);
> +            src++;
> +        } else if (v >= 0xC1) {
> +            v -= 0xC0;
> +            do {
> +                int length = FFMIN3(v, width - x, src_end - src);
> +                if (src_end - src < length)
> +                    break;
> +                memcpy_rgb332_to_bgr8(dst + y*linesize + x, src, length);
> +                INC_XY(length);
> +                src += length;
> +                v   -= length;
> +            } while (v > 0);
> +        } else {
> +            return -1;
> +        }
> +    }
> +    return 0;
> +}
> +
> +static int sgirle_decode_frame(AVCodecContext *avctx,
> +                            void *data, int *data_size,

s/data_size/got_frame
> +                            AVPacket *avpkt)
> +{
> +    SgiContext *s = avctx->priv_data;
> +
> +    s->frame.reference = 3;
> +    s->frame.buffer_hints = FF_BUFFER_HINTS_VALID |
> FF_BUFFER_HINTS_PRESERVE |
> +                            FF_BUFFER_HINTS_REUSABLE |
> FF_BUFFER_HINTS_READABLE;
> +    if (avctx->reget_buffer(avctx, &s->frame)) {
> +        av_log (avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
> +        return -1;

return meaningful error.
> +    }
> +
> +    if (decode_sgirle8(s->frame.data[0], avpkt->data, avpkt->size,
> avctx->width, avctx->height, s->frame.linesize[0]) < 0)
> +        av_log_ask_for_sample(avctx, "unknown opcode\n");

if decoding fails *got_frame is 0 and return is < 0 (AVERROR_INVALIDDATA).
> +
> +    *data_size = sizeof(AVFrame);

This is "*got_frame = 1;" actually, check other decoders.
> +    *(AVFrame*)data = s->frame;
> +
> +    return avpkt->size;
> +}
> +
> +static av_cold int sgirle_decode_end(AVCodecContext *avctx)
> +{
> +    SgiContext *s = avctx->priv_data;
> +
> +    if (s->frame.data[0])
> +        avctx->release_buffer(avctx, &s->frame);
> +
> +    return 0;
> +}
> +
> +AVCodec ff_sgirle_decoder = {
> +    .name           = "sgirle",
> +    .type           = AVMEDIA_TYPE_VIDEO,
> +    .id             = AV_CODEC_ID_SGIRLE,
> +    .priv_data_size = sizeof(SgiContext),
> +    .init           = sgirle_decode_init,
> +    .close          = sgirle_decode_end,
> +    .decode         = sgirle_decode_frame,
> +    .capabilities   = CODEC_CAP_DR1,
> +    .long_name      = NULL_IF_CONFIG_SMALL("SGI RLE 8-bit"),
> +};
> --
> 1.8.0
>
> -- Peter
> (A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
>


More information about the ffmpeg-devel mailing list