/*
  * Copyright (c) 2003 Michael Niedermayer
  *

  * 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
  * ASUS V1/V2 decoder.
  */
 

 #include "libavutil/attributes.h"

 #include "libavutil/mem.h"
 
 #include "asv.h"
 #include "avcodec.h"

 #include "blockdsp.h"

 #include "idctdsp.h"

 #include "internal.h"

 #include "mathops.h"

 #include "mpeg12data.h"
 

 #define VLC_BITS             6

 #define ASV2_LEVEL_VLC_BITS 10
 
 static VLC ccp_vlc;
 static VLC level_vlc;
 static VLC dc_ccp_vlc;
 static VLC ac_ccp_vlc;
 static VLC asv2_level_vlc;
 

 static av_cold void init_vlcs(ASV1Context *a)
 {

     static int done = 0;
 
     if (!done) {
         done = 1;
 
         INIT_VLC_STATIC(&ccp_vlc, VLC_BITS, 17,

                         &ff_asv_ccp_tab[0][1], 2, 1,
                         &ff_asv_ccp_tab[0][0], 2, 1, 64);

         INIT_VLC_STATIC(&dc_ccp_vlc, VLC_BITS, 8,

                         &ff_asv_dc_ccp_tab[0][1], 2, 1,
                         &ff_asv_dc_ccp_tab[0][0], 2, 1, 64);

         INIT_VLC_STATIC(&ac_ccp_vlc, VLC_BITS, 16,

                         &ff_asv_ac_ccp_tab[0][1], 2, 1,
                         &ff_asv_ac_ccp_tab[0][0], 2, 1, 64);

         INIT_VLC_STATIC(&level_vlc,  VLC_BITS, 7,

                         &ff_asv_level_tab[0][1], 2, 1,
                         &ff_asv_level_tab[0][0], 2, 1, 64);

         INIT_VLC_STATIC(&asv2_level_vlc, ASV2_LEVEL_VLC_BITS, 63,

                         &ff_asv2_level_tab[0][1], 2, 1,
                         &ff_asv2_level_tab[0][0], 2, 1, 1024);

     }
 }
 

 // FIXME write a reversed bitstream reader to avoid the double reverse

 static inline int asv2_get_bits(GetBitContext *gb, int n)
 {

     return ff_reverse[get_bits(gb, n) << (8 - n)];

 }
 

 static inline int asv1_get_level(GetBitContext *gb)
 {
     int code = get_vlc2(gb, level_vlc.table, VLC_BITS, 1);

     if (code == 3)
         return get_sbits(gb, 8);
     else
         return code - 3;

 }
 

 static inline int asv2_get_level(GetBitContext *gb)
 {
     int code = get_vlc2(gb, asv2_level_vlc.table, ASV2_LEVEL_VLC_BITS, 1);

     if (code == 31)

         return (int8_t) asv2_get_bits(gb, 8);

     else
         return code - 31;

 }
 

 static inline int asv1_decode_block(ASV1Context *a, int16_t block[64])

 {

     int i;
 

     block[0] = 8 * get_bits(&a->gb, 8);

     for (i = 0; i < 11; i++) {
         const int ccp = get_vlc2(&a->gb, ccp_vlc.table, VLC_BITS, 1);

         if (ccp) {
             if (ccp == 16)
                 break;
             if (ccp < 0 || i >= 10) {

                 av_log(a->avctx, AV_LOG_ERROR, "coded coeff pattern damaged\n");

                 return AVERROR_INVALIDDATA;

             }
 

             if (ccp & 8)
                 block[a->scantable.permutated[4 * i + 0]] = (asv1_get_level(&a->gb) * a->intra_matrix[4 * i + 0]) >> 4;
             if (ccp & 4)
                 block[a->scantable.permutated[4 * i + 1]] = (asv1_get_level(&a->gb) * a->intra_matrix[4 * i + 1]) >> 4;
             if (ccp & 2)
                 block[a->scantable.permutated[4 * i + 2]] = (asv1_get_level(&a->gb) * a->intra_matrix[4 * i + 2]) >> 4;
             if (ccp & 1)
                 block[a->scantable.permutated[4 * i + 3]] = (asv1_get_level(&a->gb) * a->intra_matrix[4 * i + 3]) >> 4;

         }
     }
 
     return 0;
 }
 

 static inline int asv2_decode_block(ASV1Context *a, int16_t block[64])

 {

     int i, count, ccp;
 

     count = asv2_get_bits(&a->gb, 4);

     block[0] = 8 * asv2_get_bits(&a->gb, 8);

     ccp = get_vlc2(&a->gb, dc_ccp_vlc.table, VLC_BITS, 1);
     if (ccp) {
         if (ccp & 4)
             block[a->scantable.permutated[1]] = (asv2_get_level(&a->gb) * a->intra_matrix[1]) >> 4;
         if (ccp & 2)
             block[a->scantable.permutated[2]] = (asv2_get_level(&a->gb) * a->intra_matrix[2]) >> 4;
         if (ccp & 1)
             block[a->scantable.permutated[3]] = (asv2_get_level(&a->gb) * a->intra_matrix[3]) >> 4;

     }
 

     for (i = 1; i < count + 1; i++) {
         const int ccp = get_vlc2(&a->gb, ac_ccp_vlc.table, VLC_BITS, 1);
 
         if (ccp) {
             if (ccp & 8)

                 block[a->scantable.permutated[4 * i + 0]] = (asv2_get_level(&a->gb) * a->intra_matrix[4 * i + 0]) >> 4;

             if (ccp & 4)

                 block[a->scantable.permutated[4 * i + 1]] = (asv2_get_level(&a->gb) * a->intra_matrix[4 * i + 1]) >> 4;

             if (ccp & 2)

                 block[a->scantable.permutated[4 * i + 2]] = (asv2_get_level(&a->gb) * a->intra_matrix[4 * i + 2]) >> 4;

             if (ccp & 1)

                 block[a->scantable.permutated[4 * i + 3]] = (asv2_get_level(&a->gb) * a->intra_matrix[4 * i + 3]) >> 4;

         }
     }
 
     return 0;
 }
 

 static inline int decode_mb(ASV1Context *a, int16_t block[6][64])

 {

     int i, ret;

     a->bdsp.clear_blocks(block[0]);

     if (a->avctx->codec_id == AV_CODEC_ID_ASV1) {
         for (i = 0; i < 6; i++) {

             if ((ret = asv1_decode_block(a, block[i])) < 0)
                 return ret;

         }

     } else {
         for (i = 0; i < 6; i++) {

             if ((ret = asv2_decode_block(a, block[i])) < 0)
                 return ret;

         }
     }
     return 0;
 }
 

 static inline void idct_put(ASV1Context *a, AVFrame *frame, int mb_x, int mb_y)

 {

     int16_t(*block)[64] = a->block;
     int linesize = frame->linesize[0];

     uint8_t *dest_y  = frame->data[0] + (mb_y * 16 * linesize)           + mb_x * 16;
     uint8_t *dest_cb = frame->data[1] + (mb_y *  8 * frame->linesize[1]) + mb_x *  8;
     uint8_t *dest_cr = frame->data[2] + (mb_y *  8 * frame->linesize[2]) + mb_x *  8;

     a->idsp.idct_put(dest_y,                    linesize, block[0]);
     a->idsp.idct_put(dest_y + 8,                linesize, block[1]);
     a->idsp.idct_put(dest_y + 8 * linesize,     linesize, block[2]);
     a->idsp.idct_put(dest_y + 8 * linesize + 8, linesize, block[3]);

     if (!(a->avctx->flags & AV_CODEC_FLAG_GRAY)) {

         a->idsp.idct_put(dest_cb, frame->linesize[1], block[4]);
         a->idsp.idct_put(dest_cr, frame->linesize[2], block[5]);

     }
 }
 

 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,

                         AVPacket *avpkt)
 {

     ASV1Context *const a = avctx->priv_data;
     const uint8_t *buf = avpkt->data;
     int buf_size       = avpkt->size;
     AVFrame *const p = data;

     int mb_x, mb_y, ret;

     if (buf_size * 8LL < a->mb_height * a->mb_width * 13LL)

         return AVERROR_INVALIDDATA;
 

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

         return ret;

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

 
     av_fast_padded_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size,
                           buf_size);
     if (!a->bitstream_buffer)
         return AVERROR(ENOMEM);
 

     if (avctx->codec_id == AV_CODEC_ID_ASV1) {

         a->bbdsp.bswap_buf((uint32_t *) a->bitstream_buffer,
                            (const uint32_t *) buf, buf_size / 4);

     } else {

         int i;

         for (i = 0; i < buf_size; i++)
             a->bitstream_buffer[i] = ff_reverse[buf[i]];

     }
 

     init_get_bits(&a->gb, a->bitstream_buffer, buf_size * 8);

     for (mb_y = 0; mb_y < a->mb_height2; mb_y++) {
         for (mb_x = 0; mb_x < a->mb_width2; mb_x++) {

             if ((ret = decode_mb(a, a->block)) < 0)
                 return ret;

             idct_put(a, p, mb_x, mb_y);

         }
     }
 

     if (a->mb_width2 != a->mb_width) {
         mb_x = a->mb_width2;
         for (mb_y = 0; mb_y < a->mb_height2; mb_y++) {

             if ((ret = decode_mb(a, a->block)) < 0)
                 return ret;

             idct_put(a, p, mb_x, mb_y);

         }
     }
 

     if (a->mb_height2 != a->mb_height) {
         mb_y = a->mb_height2;
         for (mb_x = 0; mb_x < a->mb_width; mb_x++) {

             if ((ret = decode_mb(a, a->block)) < 0)
                 return ret;

             idct_put(a, p, mb_x, mb_y);

         }
     }
 

     *got_frame = 1;

 
     emms_c();
 

     return (get_bits_count(&a->gb) + 31) / 32 * 4;

 }
 

 static av_cold int decode_init(AVCodecContext *avctx)
 {

     ASV1Context *const a = avctx->priv_data;
     const int scale      = avctx->codec_id == AV_CODEC_ID_ASV1 ? 1 : 2;

     int i;
 

     if (avctx->extradata_size < 1) {

         av_log(avctx, AV_LOG_WARNING, "No extradata provided\n");

     }
 

     ff_asv_common_init(avctx);

     ff_blockdsp_init(&a->bdsp, avctx);

     ff_idctdsp_init(&a->idsp, avctx);

     init_vlcs(a);

     ff_init_scantable(a->idsp.idct_permutation, &a->scantable, ff_asv_scantab);

     avctx->pix_fmt = AV_PIX_FMT_YUV420P;

     if (avctx->extradata_size < 1 || (a->inv_qscale = avctx->extradata[0]) == 0) {

         av_log(avctx, AV_LOG_ERROR, "illegal qscale 0\n");

         if (avctx->codec_id == AV_CODEC_ID_ASV1)
             a->inv_qscale = 6;

         else

             a->inv_qscale = 10;

     }
 

     for (i = 0; i < 64; i++) {

         int index = ff_asv_scantab[i];
 

         a->intra_matrix[i] = 64 * scale * ff_mpeg1_default_intra_matrix[index] /
                              a->inv_qscale;

     }
 
     return 0;
 }
 

 static av_cold int decode_end(AVCodecContext *avctx)
 {

     ASV1Context *const a = avctx->priv_data;

 
     av_freep(&a->bitstream_buffer);

     a->bitstream_buffer_size = 0;

 
     return 0;
 }
 

 #if CONFIG_ASV1_DECODER

 AVCodec ff_asv1_decoder = {
     .name           = "asv1",

     .long_name      = NULL_IF_CONFIG_SMALL("ASUS V1"),

     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_ASV1,
     .priv_data_size = sizeof(ASV1Context),
     .init           = decode_init,
     .close          = decode_end,
     .decode         = decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1,

 };

 #endif

 #if CONFIG_ASV2_DECODER

 AVCodec ff_asv2_decoder = {
     .name           = "asv2",

     .long_name      = NULL_IF_CONFIG_SMALL("ASUS V2"),

     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_ASV2,
     .priv_data_size = sizeof(ASV1Context),
     .init           = decode_init,
     .close          = decode_end,
     .decode         = decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1,

 };

 #endif