/*
  * Cirrus Logic AccuPak (CLJR) codec
  * Copyright (c) 2003 Alex Beregszaszi
  *

  * 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

  * Cirrus Logic AccuPak codec.
  */

 #include "avcodec.h"

 #include "libavutil/opt.h"

 #include "get_bits.h"

 #include "put_bits.h"

 typedef struct CLJRContext {

     AVClass        *avclass;

     AVFrame         picture;

     int             dither_type;

 } CLJRContext;
 

 static av_cold int common_init(AVCodecContext *avctx)
 {
     CLJRContext * const a = avctx->priv_data;
 

     avcodec_get_frame_defaults(&a->picture);

     avctx->coded_frame = &a->picture;

 
     return 0;
 }
 
 #if CONFIG_CLJR_DECODER

 static int decode_frame(AVCodecContext *avctx,

                         void *data, int *data_size,

                         AVPacket *avpkt)

 {

     const uint8_t *buf = avpkt->data;

     int buf_size       = avpkt->size;

     CLJRContext * const a = avctx->priv_data;

     GetBitContext gb;

     AVFrame *picture = data;

     AVFrame * const p = &a->picture;

     int x, y;

     if (p->data[0])

         avctx->release_buffer(avctx, p);
 

     if (avctx->height <= 0 || avctx->width <= 0) {
         av_log(avctx, AV_LOG_ERROR, "Invalid width or height\n");
         return AVERROR_INVALIDDATA;
     }
 

     if (buf_size < avctx->height * avctx->width) {

         av_log(avctx, AV_LOG_ERROR,
                "Resolution larger than buffer size. Invalid header?\n");

         return AVERROR_INVALIDDATA;

     }
 

     p->reference = 0;
     if (avctx->get_buffer(avctx, p) < 0) {

         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

         return -1;
     }

     p->pict_type = AV_PICTURE_TYPE_I;
     p->key_frame = 1;

     init_get_bits(&gb, buf, buf_size * 8);

     for (y = 0; y < avctx->height; y++) {
         uint8_t *luma = &a->picture.data[0][y * a->picture.linesize[0]];
         uint8_t *cb   = &a->picture.data[1][y * a->picture.linesize[1]];
         uint8_t *cr   = &a->picture.data[2][y * a->picture.linesize[2]];
         for (x = 0; x < avctx->width; x += 4) {

             luma[3] = (get_bits(&gb, 5)*33) >> 2;
             luma[2] = (get_bits(&gb, 5)*33) >> 2;
             luma[1] = (get_bits(&gb, 5)*33) >> 2;
             luma[0] = (get_bits(&gb, 5)*33) >> 2;

             luma += 4;

             *(cb++) = get_bits(&gb, 6) << 2;
             *(cr++) = get_bits(&gb, 6) << 2;

         }
     }
 

     *picture   = a->picture;

     *data_size = sizeof(AVPicture);
 
     return buf_size;
 }
 

 static av_cold int decode_init(AVCodecContext *avctx)
 {
     avctx->pix_fmt = PIX_FMT_YUV411P;
     return common_init(avctx);

 }
 

 static av_cold int decode_end(AVCodecContext *avctx)
 {
     CLJRContext *a = avctx->priv_data;

     if (a->picture.data[0])
         avctx->release_buffer(avctx, &a->picture);

     return 0;
 }
 

 AVCodec ff_cljr_decoder = {

     .name           = "cljr",
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = CODEC_ID_CLJR,
     .priv_data_size = sizeof(CLJRContext),
     .init           = decode_init,

     .close          = decode_end,

     .decode         = decode_frame,
     .capabilities   = CODEC_CAP_DR1,

     .long_name      = NULL_IF_CONFIG_SMALL("Cirrus Logic AccuPak"),

 };

 #endif

 #if CONFIG_CLJR_ENCODER

 static int encode_frame(AVCodecContext *avctx, unsigned char *buf,
                         int buf_size, void *data)
 {

     CLJRContext *a = avctx->priv_data;

     PutBitContext pb;
     AVFrame *p = data;
     int x, y;

     uint32_t dither= avctx->frame_number;

     static const uint32_t ordered_dither[2][2] =
     {
         { 0x10400000, 0x104F0000 },
         { 0xCB2A0000, 0xCB250000 },
     };

     p->pict_type = AV_PICTURE_TYPE_I;
     p->key_frame = 1;

     init_put_bits(&pb, buf, buf_size / 8);
 
     for (y = 0; y < avctx->height; y++) {
         uint8_t *luma = &p->data[0][y * p->linesize[0]];
         uint8_t *cb   = &p->data[1][y * p->linesize[1]];
         uint8_t *cr   = &p->data[2][y * p->linesize[2]];
         for (x = 0; x < avctx->width; x += 4) {

             switch (a->dither_type) {
             case 0: dither = 0x492A0000;                       break;
             case 1: dither = dither * 1664525 + 1013904223;    break;

             case 2: dither = ordered_dither[ y&1 ][ (x>>2)&1 ];break;

             }

             put_bits(&pb, 5, (249*(luma[3] +  (dither>>29)   )) >> 11);
             put_bits(&pb, 5, (249*(luma[2] + ((dither>>26)&7))) >> 11);
             put_bits(&pb, 5, (249*(luma[1] + ((dither>>23)&7))) >> 11);
             put_bits(&pb, 5, (249*(luma[0] + ((dither>>20)&7))) >> 11);

             luma += 4;

             put_bits(&pb, 6, (253*(*(cb++) + ((dither>>18)&3))) >> 10);
             put_bits(&pb, 6, (253*(*(cr++) + ((dither>>16)&3))) >> 10);

         }
     }

     flush_put_bits(&pb);

     return put_bits_count(&pb) / 8;

 }
 

 #define OFFSET(x) offsetof(CLJRContext, x)
 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {
     { "dither_type",   "Dither type",   OFFSET(dither_type),        AV_OPT_TYPE_INT, { .dbl=1 }, 0, 2, VE},
     { NULL },
 };
 
 static const AVClass class = {
     .class_name = "cljr encoder",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 

 AVCodec ff_cljr_encoder = {

     .name           = "cljr",
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = CODEC_ID_CLJR,
     .priv_data_size = sizeof(CLJRContext),

     .init           = common_init,

     .encode         = encode_frame,

     .pix_fmts       = (const enum PixelFormat[]) { PIX_FMT_YUV411P,
                                                    PIX_FMT_NONE },
     .long_name      = NULL_IF_CONFIG_SMALL("Cirrus Logic AccuPak"),

     .priv_class     = &class,

 };

 #endif