/*
  * Fraps FPS1 decoder
  * Copyright (c) 2005 Roine Gustafsson

  * Copyright (c) 2006 Konstantin Shishkov

  *

  * 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

  * Lossless Fraps 'FPS1' decoder

  * @author Roine Gustafsson (roine at users sf net)

  * @author Konstantin Shishkov

  *

  * Codec algorithm for version 0 is taken from Transcode <www.transcoding.org>
  *

  * Version 2 files support by Konstantin Shishkov

  */

 #include "avcodec.h"

 #include "get_bits.h"

 #include "huffman.h"
 #include "bytestream.h"

 #include "dsputil.h"

 #include "internal.h"

 #include "thread.h"

 #define FPS_TAG MKTAG('F', 'P', 'S', 'x')

 #define VLC_BITS 11

 
 /**
  * local variable storage
  */

 typedef struct FrapsContext {

     AVCodecContext *avctx;

     uint8_t *tmpbuf;

     int tmpbuf_size;

     DSPContext dsp;

 } FrapsContext;
 
 
 /**
  * initializes decoder
  * @param avctx codec context
  * @return 0 on success or negative if fails
  */

 static av_cold int decode_init(AVCodecContext *avctx)

 {
     FrapsContext * const s = avctx->priv_data;
 

     s->avctx  = avctx;

     s->tmpbuf = NULL;
 

     ff_dsputil_init(&s->dsp, avctx);

 
     return 0;
 }
 

 /**
  * Comparator - our nodes should ascend by count
  * but with preserved symbol order
  */

 static int huff_cmp(const void *va, const void *vb)
 {

     const Node *a = va, *b = vb;

     return (a->count - b->count)*256 + a->sym - b->sym;
 }
 
 /**
  * decode Fraps v2 packed plane
  */
 static int fraps2_decode_plane(FrapsContext *s, uint8_t *dst, int stride, int w,

                                int h, const uint8_t *src, int size, int Uoff,
                                const int step)

 {

     int i, j, ret;

     GetBitContext gb;
     VLC vlc;

     Node nodes[512];

     for (i = 0; i < 256; i++)

         nodes[i].count = bytestream_get_le32(&src);
     size -= 1024;

     if ((ret = ff_huff_build_tree(s->avctx, &vlc, 256, VLC_BITS,

                                   nodes, huff_cmp,

                                   FF_HUFFMAN_FLAG_ZERO_COUNT)) < 0)
         return ret;

     /* we have built Huffman table and are ready to decode plane */
 
     /* convert bits so they may be used by standard bitreader */

     s->dsp.bswap_buf((uint32_t *)s->tmpbuf, (const uint32_t *)src, size >> 2);

 
     init_get_bits(&gb, s->tmpbuf, size * 8);

     for (j = 0; j < h; j++) {
         for (i = 0; i < w*step; i += step) {

             dst[i] = get_vlc2(&gb, vlc.table, VLC_BITS, 3);

             /* lines are stored as deltas between previous lines
              * and we need to add 0x80 to the first lines of chroma planes
              */

             if (j)
                 dst[i] += dst[i - stride];
             else if (Uoff)
                 dst[i] += 0x80;

             if (get_bits_left(&gb) < 0) {

                 ff_free_vlc(&vlc);

                 return AVERROR_INVALIDDATA;

             }

         }
         dst += stride;
     }

     ff_free_vlc(&vlc);

     return 0;
 }

 static int decode_frame(AVCodecContext *avctx,

                         void *data, int *got_frame,

                         AVPacket *avpkt)

 {
     FrapsContext * const s = avctx->priv_data;

     const uint8_t *buf     = avpkt->data;
     int buf_size           = avpkt->size;

     ThreadFrame frame = { .f = data };
     AVFrame * const f = data;

     uint32_t header;
     unsigned int version,header_size;
     unsigned int x, y;

     const uint32_t *buf32;

     uint32_t *luma1,*luma2,*cb,*cr;

     uint32_t offs[4];

     int i, j, ret, is_chroma;

     const int planes = 3;

     uint8_t *out;

     if (buf_size < 4) {
         av_log(avctx, AV_LOG_ERROR, "Packet is too short\n");
         return AVERROR_INVALIDDATA;
     }

     header      = AV_RL32(buf);
     version     = header & 0xff;

     header_size = (header & (1<<30))? 8 : 4; /* bit 30 means pad to 8 bytes */
 

     if (version > 5) {

         av_log(avctx, AV_LOG_ERROR,

                "This file is encoded with Fraps version %d. " \

                "This codec can only decode versions <= 5.\n", version);

         return AVERROR_PATCHWELCOME;

     }
 

     buf += header_size;

     if (version < 2) {

         unsigned needed_size = avctx->width * avctx->height * 3;

         if (version == 0) needed_size /= 2;
         needed_size += header_size;

         /* bit 31 means same as previous pic */
         if (header & (1U<<31)) {

             *got_frame = 0;

             return buf_size;
         }

         if (buf_size != needed_size) {
             av_log(avctx, AV_LOG_ERROR,
                    "Invalid frame length %d (should be %d)\n",
                    buf_size, needed_size);

             return AVERROR_INVALIDDATA;

         }

     } else {
         /* skip frame */
         if (buf_size == 8) {

             *got_frame = 0;

             return buf_size;
         }

         if (AV_RL32(buf) != FPS_TAG || buf_size < planes*1024 + 24) {
             av_log(avctx, AV_LOG_ERROR, "Fraps: error in data stream\n");

             return AVERROR_INVALIDDATA;

         }

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

             offs[i] = AV_RL32(buf + 4 + i * 4);

             if (offs[i] >= buf_size - header_size || (i && offs[i] <= offs[i - 1] + 1024)) {

                 av_log(avctx, AV_LOG_ERROR, "Fraps: plane %i offset is out of bounds\n", i);

                 return AVERROR_INVALIDDATA;

             }
         }

         offs[planes] = buf_size - header_size;

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

             av_fast_padded_malloc(&s->tmpbuf, &s->tmpbuf_size, offs[i + 1] - offs[i] - 1024);
             if (!s->tmpbuf)
                 return AVERROR(ENOMEM);
         }

     }
 

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

     avctx->pix_fmt = version & 1 ? AV_PIX_FMT_BGR24 : AV_PIX_FMT_YUVJ420P;

     avctx->color_range = version & 1 ? AVCOL_RANGE_UNSPECIFIED : AVCOL_RANGE_JPEG;

     avctx->colorspace = version & 1 ? AVCOL_SPC_UNSPECIFIED : AVCOL_SPC_BT709;

     if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)

         return ret;

     switch (version) {

     case 0:
     default:
         /* Fraps v0 is a reordered YUV420 */

         if (((avctx->width % 8) != 0) || ((avctx->height % 2) != 0)) {

             av_log(avctx, AV_LOG_ERROR, "Invalid frame size %dx%d\n",

                    avctx->width, avctx->height);

             return AVERROR_INVALIDDATA;

         }
 

         buf32 = (const uint32_t*)buf;
         for (y = 0; y < avctx->height / 2; y++) {
             luma1 = (uint32_t*)&f->data[0][  y * 2      * f->linesize[0] ];
             luma2 = (uint32_t*)&f->data[0][ (y * 2 + 1) * f->linesize[0] ];
             cr    = (uint32_t*)&f->data[1][  y          * f->linesize[1] ];
             cb    = (uint32_t*)&f->data[2][  y          * f->linesize[2] ];
             for (x = 0; x < avctx->width; x += 8) {

                 *luma1++ = *buf32++;
                 *luma1++ = *buf32++;
                 *luma2++ = *buf32++;
                 *luma2++ = *buf32++;
                 *cr++    = *buf32++;
                 *cb++    = *buf32++;

             }

         }

         break;
 
     case 1:
         /* Fraps v1 is an upside-down BGR24 */

             for (y = 0; y<avctx->height; y++)

                 memcpy(&f->data[0][(avctx->height - y - 1) * f->linesize[0]],

                        &buf[y * avctx->width * 3],
                        3 * avctx->width);

         break;
 
     case 2:

     case 4:

         /**

          * Fraps v2 is Huffman-coded YUV420 planes

          * Fraps v4 is virtually the same

          */

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

             is_chroma = !!i;

             if ((ret = fraps2_decode_plane(s, f->data[i], f->linesize[i],
                                            avctx->width  >> is_chroma,
                                            avctx->height >> is_chroma,
                                            buf + offs[i], offs[i + 1] - offs[i],
                                            is_chroma, 1)) < 0) {

                 av_log(avctx, AV_LOG_ERROR, "Error decoding plane %i\n", i);

                 return ret;

             }
         }

         break;

     case 3:

     case 5:
         /* Virtually the same as version 4, but is for RGB24 */

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

             if ((ret = fraps2_decode_plane(s, f->data[0] + i + (f->linesize[0] * (avctx->height - 1)),
                                            -f->linesize[0], avctx->width, avctx->height,
                                            buf + offs[i], offs[i + 1] - offs[i], 0, 3)) < 0) {

                 av_log(avctx, AV_LOG_ERROR, "Error decoding plane %i\n", i);

                 return ret;

             }
         }

         out = f->data[0];

         // convert pseudo-YUV into real RGB

         for (j = 0; j < avctx->height; j++) {

             uint8_t *line_end = out + 3*avctx->width;
             while (out < line_end) {
                 out[0]  += out[1];
                 out[2]  += out[1];
                 out += 3;

             }

             out += f->linesize[0] - 3*avctx->width;

         }

         break;

     }
 

     *got_frame = 1;

 
     return buf_size;
 }
 
 
 /**
  * closes decoder
  * @param avctx codec context
  * @return 0 on success or negative if fails
  */

 static av_cold int decode_end(AVCodecContext *avctx)

 {
     FrapsContext *s = (FrapsContext*)avctx->priv_data;
 

     av_freep(&s->tmpbuf);

     return 0;
 }
 
 

 AVCodec ff_fraps_decoder = {

     .name           = "fraps",

     .long_name      = NULL_IF_CONFIG_SMALL("Fraps"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_FRAPS,

     .priv_data_size = sizeof(FrapsContext),
     .init           = decode_init,
     .close          = decode_end,
     .decode         = decode_frame,

     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS,

 };