/*
  * Canopus Lossless Codec decoder
  *

  * Copyright (c) 2012-2013 Derek Buitenhuis

  *
  * 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
  */
 

 #include <inttypes.h>
 

 #include "libavutil/intreadwrite.h"

 #include "bswapdsp.h"

 #include "get_bits.h"
 #include "avcodec.h"

 #include "internal.h"

 
 typedef struct CLLCContext {
     AVCodecContext *avctx;

     BswapDSPContext bdsp;

 
     uint8_t *swapped_buf;
     int      swapped_buf_size;
 } CLLCContext;
 
 static int read_code_table(CLLCContext *ctx, GetBitContext *gb, VLC *vlc)
 {
     uint8_t symbols[256];
     uint8_t bits[256];
     uint16_t codes[256];
     int num_lens, num_codes, num_codes_sum, prefix;
     int i, j, count;
 
     prefix        = 0;
     count         = 0;
     num_codes_sum = 0;
 
     num_lens = get_bits(gb, 5);
 
     for (i = 0; i < num_lens; i++) {
         num_codes      = get_bits(gb, 9);
         num_codes_sum += num_codes;
 
         if (num_codes_sum > 256) {
             vlc->table = NULL;
 
             av_log(ctx->avctx, AV_LOG_ERROR,
                    "Too many VLCs (%d) to be read.\n", num_codes_sum);
             return AVERROR_INVALIDDATA;
         }
 
         for (j = 0; j < num_codes; j++) {
             symbols[count] = get_bits(gb, 8);
             bits[count]    = i + 1;
             codes[count]   = prefix++;
 
             count++;
         }
 
         prefix <<= 1;
     }
 
     return ff_init_vlc_sparse(vlc, 7, count, bits, 1, 1,
                               codes, 2, 2, symbols, 1, 1, 0);
 }
 

 /*
  * Unlike the RGB24 read/restore, which reads in a component at a time,
  * ARGB read/restore reads in ARGB quads.
  */
 static int read_argb_line(CLLCContext *ctx, GetBitContext *gb, int *top_left,
                           VLC *vlc, uint8_t *outbuf)
 {
     uint8_t *dst;
     int pred[4];
     int code;
     int i;
 
     OPEN_READER(bits, gb);
 
     dst     = outbuf;
     pred[0] = top_left[0];
     pred[1] = top_left[1];
     pred[2] = top_left[2];
     pred[3] = top_left[3];
 
     for (i = 0; i < ctx->avctx->width; i++) {
         /* Always get the alpha component */
         UPDATE_CACHE(bits, gb);
         GET_VLC(code, bits, gb, vlc[0].table, 7, 2);
 
         pred[0] += code;
         dst[0]   = pred[0];
 
         /* Skip the components if they are  entirely transparent */
         if (dst[0]) {
             /* Red */
             UPDATE_CACHE(bits, gb);
             GET_VLC(code, bits, gb, vlc[1].table, 7, 2);
 
             pred[1] += code;
             dst[1]   = pred[1];
 
             /* Green */
             UPDATE_CACHE(bits, gb);
             GET_VLC(code, bits, gb, vlc[2].table, 7, 2);
 
             pred[2] += code;
             dst[2]   = pred[2];
 
             /* Blue */
             UPDATE_CACHE(bits, gb);
             GET_VLC(code, bits, gb, vlc[3].table, 7, 2);
 
             pred[3] += code;
             dst[3]   = pred[3];
         } else {
             dst[1] = 0;
             dst[2] = 0;
             dst[3] = 0;
         }
 
         dst += 4;
     }
 
     CLOSE_READER(bits, gb);
 

     top_left[0]  = outbuf[0];

 
     /* Only stash components if they are not transparent */
     if (top_left[0]) {

         top_left[1] = outbuf[1];
         top_left[2] = outbuf[2];
         top_left[3] = outbuf[3];

     }
 
     return 0;
 }
 

 static int read_rgb24_component_line(CLLCContext *ctx, GetBitContext *gb,
                                      int *top_left, VLC *vlc, uint8_t *outbuf)

 {
     uint8_t *dst;
     int pred, code;
     int i;
 
     OPEN_READER(bits, gb);
 
     dst  = outbuf;
     pred = *top_left;
 
     /* Simultaneously read and restore the line */
     for (i = 0; i < ctx->avctx->width; i++) {
         UPDATE_CACHE(bits, gb);
         GET_VLC(code, bits, gb, vlc->table, 7, 2);
 
         pred  += code;
         dst[0] = pred;
         dst   += 3;
     }
 
     CLOSE_READER(bits, gb);
 
     /* Stash the first pixel */

     *top_left = outbuf[0];

 
     return 0;
 }
 

 static int read_yuv_component_line(CLLCContext *ctx, GetBitContext *gb,
                                    int *top_left, VLC *vlc, uint8_t *outbuf,
                                    int is_chroma)
 {
     int pred, code;
     int i;
 
     OPEN_READER(bits, gb);
 
     pred = *top_left;
 
     /* Simultaneously read and restore the line */
     for (i = 0; i < ctx->avctx->width >> is_chroma; i++) {
         UPDATE_CACHE(bits, gb);
         GET_VLC(code, bits, gb, vlc->table, 7, 2);
 
         pred     += code;
         outbuf[i] = pred;
     }
 
     CLOSE_READER(bits, gb);
 
     /* Stash the first pixel */
     *top_left = outbuf[0];
 
     return 0;
 }
 

 static int decode_argb_frame(CLLCContext *ctx, GetBitContext *gb, AVFrame *pic)
 {
     AVCodecContext *avctx = ctx->avctx;
     uint8_t *dst;
     int pred[4];
     int ret;
     int i, j;
     VLC vlc[4];
 
     pred[0] = 0;
     pred[1] = 0x80;
     pred[2] = 0x80;
     pred[3] = 0x80;
 
     dst = pic->data[0];
 
     skip_bits(gb, 16);
 
     /* Read in code table for each plane */
     for (i = 0; i < 4; i++) {
         ret = read_code_table(ctx, gb, &vlc[i]);
         if (ret < 0) {
             for (j = 0; j <= i; j++)
                 ff_free_vlc(&vlc[j]);
 
             av_log(ctx->avctx, AV_LOG_ERROR,
                    "Could not read code table %d.\n", i);
             return ret;
         }
     }
 
     /* Read in and restore every line */
     for (i = 0; i < avctx->height; i++) {
         read_argb_line(ctx, gb, pred, vlc, dst);
 
         dst += pic->linesize[0];
     }
 
     for (i = 0; i < 4; i++)
         ff_free_vlc(&vlc[i]);
 
     return 0;
 }
 

 static int decode_rgb24_frame(CLLCContext *ctx, GetBitContext *gb, AVFrame *pic)

 {
     AVCodecContext *avctx = ctx->avctx;
     uint8_t *dst;
     int pred[3];
     int ret;
     int i, j;
     VLC vlc[3];
 
     pred[0] = 0x80;
     pred[1] = 0x80;
     pred[2] = 0x80;
 
     dst = pic->data[0];
 
     skip_bits(gb, 16);
 
     /* Read in code table for each plane */
     for (i = 0; i < 3; i++) {
         ret = read_code_table(ctx, gb, &vlc[i]);
         if (ret < 0) {
             for (j = 0; j <= i; j++)
                 ff_free_vlc(&vlc[j]);
 
             av_log(ctx->avctx, AV_LOG_ERROR,
                    "Could not read code table %d.\n", i);
             return ret;
         }
     }
 
     /* Read in and restore every line */
     for (i = 0; i < avctx->height; i++) {
         for (j = 0; j < 3; j++)

             read_rgb24_component_line(ctx, gb, &pred[j], &vlc[j], &dst[j]);

 
         dst += pic->linesize[0];
     }
 
     for (i = 0; i < 3; i++)
         ff_free_vlc(&vlc[i]);
 
     return 0;
 }
 

 static int decode_yuv_frame(CLLCContext *ctx, GetBitContext *gb, AVFrame *pic)
 {
     AVCodecContext *avctx = ctx->avctx;
     uint8_t block;
     uint8_t *dst[3];
     int pred[3];
     int ret;
     int i, j;
     VLC vlc[2];
 
     pred[0] = 0x80;
     pred[1] = 0x80;
     pred[2] = 0x80;
 
     dst[0] = pic->data[0];
     dst[1] = pic->data[1];
     dst[2] = pic->data[2];
 
     skip_bits(gb, 8);
 
     block = get_bits(gb, 8);
     if (block) {
         avpriv_request_sample(ctx->avctx, "Blocked YUV");
         return AVERROR_PATCHWELCOME;
     }
 
     /* Read in code table for luma and chroma */
     for (i = 0; i < 2; i++) {
         ret = read_code_table(ctx, gb, &vlc[i]);
         if (ret < 0) {
             for (j = 0; j <= i; j++)
                 ff_free_vlc(&vlc[j]);
 
             av_log(ctx->avctx, AV_LOG_ERROR,
                    "Could not read code table %d.\n", i);
             return ret;
         }
     }
 
     /* Read in and restore every line */
     for (i = 0; i < avctx->height; i++) {
         read_yuv_component_line(ctx, gb, &pred[0], &vlc[0], dst[0], 0); /* Y */
         read_yuv_component_line(ctx, gb, &pred[1], &vlc[1], dst[1], 1); /* U */
         read_yuv_component_line(ctx, gb, &pred[2], &vlc[1], dst[2], 1); /* V */
 
         for (j = 0; j < 3; j++)
             dst[j] += pic->linesize[j];
     }
 
     for (i = 0; i < 2; i++)
         ff_free_vlc(&vlc[i]);
 
     return 0;
 }
 

 static int cllc_decode_frame(AVCodecContext *avctx, void *data,
                              int *got_picture_ptr, AVPacket *avpkt)
 {
     CLLCContext *ctx = avctx->priv_data;

     AVFrame *pic = data;

     uint8_t *src = avpkt->data;
     uint32_t info_tag, info_offset;

     int data_size;

     GetBitContext gb;
     int coding_type, ret;
 
     /* Skip the INFO header if present */
     info_offset = 0;
     info_tag    = AV_RL32(src);
     if (info_tag == MKTAG('I', 'N', 'F', 'O')) {
         info_offset = AV_RL32(src + 4);
         if (info_offset > UINT32_MAX - 8 || info_offset + 8 > avpkt->size) {
             av_log(avctx, AV_LOG_ERROR,

                    "Invalid INFO header offset: 0x%08"PRIX32" is too large.\n",

                    info_offset);
             return AVERROR_INVALIDDATA;
         }
 
         info_offset += 8;
         src         += info_offset;
 
         av_log(avctx, AV_LOG_DEBUG, "Skipping INFO chunk.\n");
     }
 

     data_size = (avpkt->size - info_offset) & ~1;
 
     /* Make sure our bswap16'd buffer is big enough */
     av_fast_padded_malloc(&ctx->swapped_buf,
                           &ctx->swapped_buf_size, data_size);
     if (!ctx->swapped_buf) {
         av_log(avctx, AV_LOG_ERROR, "Could not allocate swapped buffer.\n");
         return AVERROR(ENOMEM);
     }
 

     /* bswap16 the buffer since CLLC's bitreader works in 16-bit words */

     ctx->bdsp.bswap16_buf((uint16_t *) ctx->swapped_buf, (uint16_t *) src,
                           data_size / 2);

     if ((ret = init_get_bits8(&gb, ctx->swapped_buf, data_size)) < 0)
         return ret;

 
     /*
      * Read in coding type. The types are as follows:
      *
      * 0 - YUY2
      * 1 - BGR24 (Triples)
      * 2 - BGR24 (Quads)
      * 3 - BGRA
      */
     coding_type = (AV_RL32(src) >> 8) & 0xFF;
     av_log(avctx, AV_LOG_DEBUG, "Frame coding type: %d\n", coding_type);
 
     switch (coding_type) {

     case 0:
         avctx->pix_fmt             = AV_PIX_FMT_YUV422P;
         avctx->bits_per_raw_sample = 8;
 

         if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)

             return ret;
 
         ret = decode_yuv_frame(ctx, &gb, pic);
         if (ret < 0)
             return ret;
 
         break;

     case 1:

     case 2:

         avctx->pix_fmt             = AV_PIX_FMT_RGB24;

         avctx->bits_per_raw_sample = 8;
 

         if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)

             return ret;
 

         ret = decode_rgb24_frame(ctx, &gb, pic);

         if (ret < 0)
             return ret;
 
         break;

     case 3:

         avctx->pix_fmt             = AV_PIX_FMT_ARGB;

         avctx->bits_per_raw_sample = 8;
 

         if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)

             return ret;
 
         ret = decode_argb_frame(ctx, &gb, pic);
         if (ret < 0)
             return ret;
 
         break;

     default:

         av_log(avctx, AV_LOG_ERROR, "Unknown coding type: %d.\n", coding_type);

         return AVERROR_INVALIDDATA;
     }
 
     pic->key_frame = 1;
     pic->pict_type = AV_PICTURE_TYPE_I;
 
     *got_picture_ptr = 1;
 
     return avpkt->size;
 }
 
 static av_cold int cllc_decode_close(AVCodecContext *avctx)
 {
     CLLCContext *ctx = avctx->priv_data;
 
     av_freep(&ctx->swapped_buf);
 
     return 0;
 }
 
 static av_cold int cllc_decode_init(AVCodecContext *avctx)
 {
     CLLCContext *ctx = avctx->priv_data;
 
     /* Initialize various context values */
     ctx->avctx            = avctx;
     ctx->swapped_buf      = NULL;
     ctx->swapped_buf_size = 0;
 

     ff_bswapdsp_init(&ctx->bdsp);

 
     return 0;
 }
 
 AVCodec ff_cllc_decoder = {
     .name           = "cllc",

     .long_name      = NULL_IF_CONFIG_SMALL("Canopus Lossless Codec"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_CLLC,

     .priv_data_size = sizeof(CLLCContext),
     .init           = cllc_decode_init,
     .decode         = cllc_decode_frame,
     .close          = cllc_decode_close,
     .capabilities   = CODEC_CAP_DR1,
 };