/*
  * TDSC decoder
  * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
  *

  * 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
  * TDSC decoder
  *
  * Fourcc: TSDC
  *
  * TDSC is very simple. It codes picture by tiles, storing them in raw BGR24
  * format or compressing them in JPEG. Frames can be full pictures or just
  * updates to the previous frame. Cursor is found in its own frame or at the
  * bottom of the picture. Every frame is then packed with zlib.
  *
  * Supports: BGR24
  */
 
 #include <stdint.h>
 #include <zlib.h>
 
 #include "libavutil/imgutils.h"
 
 #include "avcodec.h"
 #include "bytestream.h"
 #include "internal.h"
 
 #define BITMAPINFOHEADER_SIZE 0x28
 #define TDSF_HEADER_SIZE      0x56
 #define TDSB_HEADER_SIZE      0x08
 
 typedef struct TDSCContext {
     AVCodecContext *jpeg_avctx;   // wrapper context for MJPEG
 
     int width, height;
     GetByteContext gbc;
 
     AVFrame *refframe;          // full decoded frame (without cursor)
     AVFrame *jpgframe;          // decoded JPEG tile
     uint8_t *tilebuffer;        // buffer containing tile data
 

     /* zlib interaction */

     uint8_t *deflatebuffer;
     uLongf deflatelen;
 
     /* All that is cursor */
     uint8_t    *cursor;
     int        cursor_stride;
     int        cursor_w, cursor_h, cursor_x, cursor_y;
     int        cursor_hot_x, cursor_hot_y;
 } TDSCContext;
 
 /* 1 byte bits, 1 byte planes, 2 bytes format (probably) */
 enum TDSCCursorFormat {
     CUR_FMT_MONO = 0x01010004,
     CUR_FMT_BGRA = 0x20010004,
     CUR_FMT_RGBA = 0x20010008,
 };
 
 static av_cold int tdsc_close(AVCodecContext *avctx)
 {
     TDSCContext *ctx = avctx->priv_data;
 
     av_frame_free(&ctx->refframe);
     av_frame_free(&ctx->jpgframe);
     av_freep(&ctx->deflatebuffer);
     av_freep(&ctx->tilebuffer);
     av_freep(&ctx->cursor);
     avcodec_free_context(&ctx->jpeg_avctx);
 
     return 0;
 }
 
 static av_cold int tdsc_init(AVCodecContext *avctx)
 {
     TDSCContext *ctx = avctx->priv_data;
     const AVCodec *codec;
     int ret;
 
     avctx->pix_fmt = AV_PIX_FMT_BGR24;
 
     /* These needs to be set to estimate buffer and frame size */
     if (!(avctx->width && avctx->height)) {
         av_log(avctx, AV_LOG_ERROR, "Video size not set.\n");
         return AVERROR_INVALIDDATA;
     }
 
     /* This value should be large enough for a RAW-only frame plus headers */
     ctx->deflatelen = avctx->width * avctx->height * (3 + 1);
     ret = av_reallocp(&ctx->deflatebuffer, ctx->deflatelen);
     if (ret < 0)
         return ret;
 
     /* Allocate reference and JPEG frame */
     ctx->refframe = av_frame_alloc();
     ctx->jpgframe = av_frame_alloc();
     if (!ctx->refframe || !ctx->jpgframe)
         return AVERROR(ENOMEM);
 
     /* Prepare everything needed for JPEG decoding */
     codec = avcodec_find_decoder(AV_CODEC_ID_MJPEG);
     if (!codec)
         return AVERROR_BUG;
     ctx->jpeg_avctx = avcodec_alloc_context3(codec);
     if (!ctx->jpeg_avctx)
         return AVERROR(ENOMEM);
     ctx->jpeg_avctx->flags = avctx->flags;
     ctx->jpeg_avctx->flags2 = avctx->flags2;
     ctx->jpeg_avctx->dct_algo = avctx->dct_algo;

     ctx->jpeg_avctx->idct_algo = avctx->idct_algo;

     ret = ff_codec_open2_recursive(ctx->jpeg_avctx, codec, NULL);

     if (ret < 0)
         return ret;
 
     /* Set the output pixel format on the reference frame */
     ctx->refframe->format = avctx->pix_fmt;
 
     return 0;
 }
 
 #define APPLY_ALPHA(src, new, alpha) \
     src = (src * (256 - alpha) + new * alpha) >> 8
 
 /* Paint a region over a buffer, without drawing out of its bounds. */
 static void tdsc_paint_cursor(AVCodecContext *avctx, uint8_t *dst, int stride)
 {
     TDSCContext *ctx = avctx->priv_data;
     const uint8_t *cursor = ctx->cursor;
     int x = ctx->cursor_x - ctx->cursor_hot_x;
     int y = ctx->cursor_y - ctx->cursor_hot_y;
     int w = ctx->cursor_w;
     int h = ctx->cursor_h;
     int i, j;
 
     if (!ctx->cursor)
         return;
 
     if (x + w > ctx->width)
         w = ctx->width - x;
     if (y + h > ctx->height)
         h = ctx->height - y;
     if (x < 0) {
         w      +=  x;
         cursor += -x * 4;
     } else {
         dst    +=  x * 3;
     }
     if (y < 0) {
         h      +=  y;
         cursor += -y * ctx->cursor_stride;
     } else {
         dst    +=  y * stride;
     }
     if (w < 0 || h < 0)
         return;
 
     for (j = 0; j < h; j++) {
         for (i = 0; i < w; i++) {
             uint8_t alpha = cursor[i * 4];
             APPLY_ALPHA(dst[i * 3 + 0], cursor[i * 4 + 1], alpha);
             APPLY_ALPHA(dst[i * 3 + 1], cursor[i * 4 + 2], alpha);
             APPLY_ALPHA(dst[i * 3 + 2], cursor[i * 4 + 3], alpha);
         }
         dst    += stride;
         cursor += ctx->cursor_stride;
     }
 }
 
 /* Load cursor data and store it in ABGR mode. */
 static int tdsc_load_cursor(AVCodecContext *avctx)
 {
     TDSCContext *ctx  = avctx->priv_data;

     int i, j, k, ret, cursor_fmt;

     uint8_t *dst;
 
     ctx->cursor_hot_x = bytestream2_get_le16(&ctx->gbc);
     ctx->cursor_hot_y = bytestream2_get_le16(&ctx->gbc);
     ctx->cursor_w     = bytestream2_get_le16(&ctx->gbc);
     ctx->cursor_h     = bytestream2_get_le16(&ctx->gbc);
 
     ctx->cursor_stride = FFALIGN(ctx->cursor_w, 32) * 4;
     cursor_fmt = bytestream2_get_le32(&ctx->gbc);
 
     if (ctx->cursor_x >= avctx->width || ctx->cursor_y >= avctx->height) {
         av_log(avctx, AV_LOG_ERROR,
                "Invalid cursor position (%d.%d outside %dx%d).\n",
                ctx->cursor_x, ctx->cursor_y, avctx->width, avctx->height);
         return AVERROR_INVALIDDATA;
     }
     if (ctx->cursor_w < 1 || ctx->cursor_w > 256 ||
         ctx->cursor_h < 1 || ctx->cursor_h > 256) {
         av_log(avctx, AV_LOG_ERROR,
                "Invalid cursor dimensions %dx%d.\n",
                ctx->cursor_w, ctx->cursor_h);
         return AVERROR_INVALIDDATA;
     }
     if (ctx->cursor_hot_x > ctx->cursor_w ||
         ctx->cursor_hot_y > ctx->cursor_h) {
         av_log(avctx, AV_LOG_WARNING, "Invalid hotspot position %d.%d.\n",
                ctx->cursor_hot_x, ctx->cursor_hot_y);
         ctx->cursor_hot_x = FFMIN(ctx->cursor_hot_x, ctx->cursor_w - 1);
         ctx->cursor_hot_y = FFMIN(ctx->cursor_hot_y, ctx->cursor_h - 1);
     }
 
     ret = av_reallocp(&ctx->cursor, ctx->cursor_stride * ctx->cursor_h);
     if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR, "Cannot allocate cursor buffer.\n");
         return ret;
     }
 
     dst = ctx->cursor;
     /* here data is packed in BE */
     switch (cursor_fmt) {
     case CUR_FMT_MONO:
         for (j = 0; j < ctx->cursor_h; j++) {
             for (i = 0; i < ctx->cursor_w; i += 32) {

                 uint32_t bits = bytestream2_get_be32(&ctx->gbc);

                 for (k = 0; k < 32; k++) {
                     dst[0] = !!(bits & 0x80000000);
                     dst   += 4;
                     bits <<= 1;
                 }
             }
             dst += ctx->cursor_stride - ctx->cursor_w * 4;
         }
 
         dst = ctx->cursor;
         for (j = 0; j < ctx->cursor_h; j++) {
             for (i = 0; i < ctx->cursor_w; i += 32) {

                 uint32_t bits = bytestream2_get_be32(&ctx->gbc);

                 for (k = 0; k < 32; k++) {
                     int mask_bit = !!(bits & 0x80000000);
                     switch (dst[0] * 2 + mask_bit) {
                     case 0:
                         dst[0] = 0xFF;
                         dst[1] = 0x00;
                         dst[2] = 0x00;
                         dst[3] = 0x00;
                         break;
                     case 1:
                         dst[0] = 0xFF;
                         dst[1] = 0xFF;
                         dst[2] = 0xFF;
                         dst[3] = 0xFF;
                         break;
                     default:
                         dst[0] = 0x00;
                         dst[1] = 0x00;
                         dst[2] = 0x00;
                         dst[3] = 0x00;
                     }
                     dst   += 4;
                     bits <<= 1;
                 }
             }
             dst += ctx->cursor_stride - ctx->cursor_w * 4;
         }
         break;
     case CUR_FMT_BGRA:
     case CUR_FMT_RGBA:
         /* Skip monochrome version of the cursor */
         bytestream2_skip(&ctx->gbc,
                          ctx->cursor_h * (FFALIGN(ctx->cursor_w, 32) >> 3));
         if (cursor_fmt & 8) { // RGBA -> ABGR
             for (j = 0; j < ctx->cursor_h; j++) {
                 for (i = 0; i < ctx->cursor_w; i++) {
                     int val = bytestream2_get_be32(&ctx->gbc);
                     *dst++ = val >> 24;
                     *dst++ = val >> 16;
                     *dst++ = val >>  8;
                     *dst++ = val >>  0;
                 }
                 dst += ctx->cursor_stride - ctx->cursor_w * 4;
             }
         } else { // BGRA -> ABGR
             for (j = 0; j < ctx->cursor_h; j++) {
                 for (i = 0; i < ctx->cursor_w; i++) {
                     int val = bytestream2_get_be32(&ctx->gbc);
                     *dst++ = val >>  0;
                     *dst++ = val >> 24;
                     *dst++ = val >> 16;
                     *dst++ = val >>  8;
                 }
                 dst += ctx->cursor_stride - ctx->cursor_w * 4;
             }
         }
         break;
     default:
         avpriv_request_sample(avctx, "Cursor format %08x", cursor_fmt);
         return AVERROR_PATCHWELCOME;
     }
 
     return 0;
 }
 
 /* Convert a single YUV pixel to RGB. */
 static inline void tdsc_yuv2rgb(uint8_t *out, int Y, int U, int V)
 {
     out[0] = av_clip_uint8(Y + (             91881 * V + 32768 >> 16));
     out[1] = av_clip_uint8(Y + (-22554 * U - 46802 * V + 32768 >> 16));
     out[2] = av_clip_uint8(Y + (116130 * U             + 32768 >> 16));
 }
 
 /* Convert a YUV420 buffer to a RGB buffer. */
 static av_always_inline void tdsc_blit(uint8_t *dst, int dst_stride,
                                        const uint8_t *srcy, int srcy_stride,
                                        const uint8_t *srcu, const uint8_t *srcv,
                                        int srcuv_stride, int width, int height)
 {
     int col, line;
     for (line = 0; line < height; line++) {
         for (col = 0; col < width; col++)
             tdsc_yuv2rgb(dst + col * 3, srcy[col],
                          srcu[col >> 1] - 128, srcv[col >> 1] - 128);
 
         dst  +=   dst_stride;
         srcy +=  srcy_stride;
         srcu += srcuv_stride * (line & 1);
         srcv += srcuv_stride * (line & 1);
     }
 }
 
 /* Invoke the MJPEG decoder to decode the tile. */
 static int tdsc_decode_jpeg_tile(AVCodecContext *avctx, int tile_size,
                                  int x, int y, int w, int h)
 {
     TDSCContext *ctx = avctx->priv_data;
     AVPacket jpkt;
     int ret;
 
     /* Prepare a packet and send to the MJPEG decoder */
     av_init_packet(&jpkt);
     jpkt.data = ctx->tilebuffer;
     jpkt.size = tile_size;
 

     ret = avcodec_send_packet(ctx->jpeg_avctx, &jpkt);
     if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR, "Error submitting a packet for decoding\n");
         return ret;
     }
 
     ret = avcodec_receive_frame(ctx->jpeg_avctx, ctx->jpgframe);
     if (ret < 0 || ctx->jpgframe->format != AV_PIX_FMT_YUVJ420P) {

         av_log(avctx, AV_LOG_ERROR,

                "JPEG decoding error (%d).\n", ret);

 
         /* Normally skip, error if explode */
         if (avctx->err_recognition & AV_EF_EXPLODE)
             return AVERROR_INVALIDDATA;
         else
             return 0;
     }
 

     /* Let's paint onto the buffer */

     tdsc_blit(ctx->refframe->data[0] + x * 3 + ctx->refframe->linesize[0] * y,
               ctx->refframe->linesize[0],
               ctx->jpgframe->data[0], ctx->jpgframe->linesize[0],
               ctx->jpgframe->data[1], ctx->jpgframe->data[2],
               ctx->jpgframe->linesize[1], w, h);
 
     av_frame_unref(ctx->jpgframe);
 
     return 0;
 }
 
 /* Parse frame and either copy data or decode JPEG. */
 static int tdsc_decode_tiles(AVCodecContext *avctx, int number_tiles)
 {
     TDSCContext *ctx = avctx->priv_data;
     int i;
 
     /* Iterate over the number of tiles */
     for (i = 0; i < number_tiles; i++) {
         int tile_size;
         int tile_mode;
         int x, y, w, h;
         int ret;
 
         if (bytestream2_get_bytes_left(&ctx->gbc) < 4 ||
             bytestream2_get_le32(&ctx->gbc) != MKTAG('T','D','S','B') ||
             bytestream2_get_bytes_left(&ctx->gbc) < TDSB_HEADER_SIZE - 4) {
             av_log(avctx, AV_LOG_ERROR, "TDSB tag is too small.\n");
             return AVERROR_INVALIDDATA;
         }
 
         tile_size = bytestream2_get_le32(&ctx->gbc);
         if (bytestream2_get_bytes_left(&ctx->gbc) < tile_size)
             return AVERROR_INVALIDDATA;
 
         tile_mode = bytestream2_get_le32(&ctx->gbc);
         bytestream2_skip(&ctx->gbc, 4); // unknown
         x = bytestream2_get_le32(&ctx->gbc);
         y = bytestream2_get_le32(&ctx->gbc);
         w = bytestream2_get_le32(&ctx->gbc) - x;
         h = bytestream2_get_le32(&ctx->gbc) - y;
 
         if (x >= ctx->width || y >= ctx->height) {
             av_log(avctx, AV_LOG_ERROR,
                    "Invalid tile position (%d.%d outside %dx%d).\n",
                    x, y, ctx->width, ctx->height);
             return AVERROR_INVALIDDATA;
         }
         if (x + w > ctx->width || y + h > ctx->height) {
             av_log(avctx, AV_LOG_ERROR,
                    "Invalid tile size %dx%d\n", w, h);
             return AVERROR_INVALIDDATA;
         }
 
         ret = av_reallocp(&ctx->tilebuffer, tile_size);
         if (!ctx->tilebuffer)
             return ret;
 
         bytestream2_get_buffer(&ctx->gbc, ctx->tilebuffer, tile_size);
 
         if (tile_mode == MKTAG('G','E','P','J')) {
             /* Decode JPEG tile and copy it in the reference frame */
             ret = tdsc_decode_jpeg_tile(avctx, tile_size, x, y, w, h);
             if (ret < 0)
                 return ret;
         } else if (tile_mode == MKTAG(' ','W','A','R')) {
             /* Just copy the buffer to output */
             av_image_copy_plane(ctx->refframe->data[0] + x * 3 +
                                 ctx->refframe->linesize[0] * y,
                                 ctx->refframe->linesize[0], ctx->tilebuffer,
                                 w * 3, w * 3, h);
         } else {
             av_log(avctx, AV_LOG_ERROR, "Unknown tile type %08x.\n", tile_mode);
             return AVERROR_INVALIDDATA;
         }
         av_log(avctx, AV_LOG_DEBUG, "Tile %d, %dx%d (%d.%d)\n", i, w, h, x, y);
     }
 
     return 0;
 }
 
 static int tdsc_parse_tdsf(AVCodecContext *avctx, int number_tiles)
 {
     TDSCContext *ctx = avctx->priv_data;
     int ret, w, h, init_refframe = !ctx->refframe->data[0];
 
     /* BITMAPINFOHEADER
      * http://msdn.microsoft.com/en-us/library/windows/desktop/dd183376.aspx */
     if (bytestream2_get_le32(&ctx->gbc) != BITMAPINFOHEADER_SIZE)
         return AVERROR_INVALIDDATA;
 
     /* Store size, but wait for context reinit before updating avctx */
     w =  bytestream2_get_le32(&ctx->gbc);
     h = -bytestream2_get_le32(&ctx->gbc);
 
     if (bytestream2_get_le16(&ctx->gbc) != 1 ||  // 1 plane
         bytestream2_get_le16(&ctx->gbc) != 24)   // BGR24
         return AVERROR_INVALIDDATA;
 
     bytestream2_skip(&ctx->gbc, 24); // unused fields
 
     /* Update sizes */
     if (avctx->width != w || avctx->height != h) {
         av_log(avctx, AV_LOG_DEBUG, "Size update %dx%d -> %d%d.\n",
                avctx->width, avctx->height, ctx->width, ctx->height);
         ret = ff_set_dimensions(avctx, w, h);
         if (ret < 0)
             return ret;
         init_refframe = 1;
     }
     ctx->refframe->width  = ctx->width  = w;
     ctx->refframe->height = ctx->height = h;
 
     /* Allocate the reference frame if not already done or on size change */
     if (init_refframe) {

         ret = av_frame_get_buffer(ctx->refframe, 0);

         if (ret < 0)
             return ret;
     }
 
     /* Decode all tiles in a frame */
     return tdsc_decode_tiles(avctx, number_tiles);
 }
 
 static int tdsc_parse_dtsm(AVCodecContext *avctx)
 {
     TDSCContext *ctx = avctx->priv_data;
     int ret;
     int action = bytestream2_get_le32(&ctx->gbc);
 
     bytestream2_skip(&ctx->gbc, 4); // some kind of ID or version maybe?
 
     if (action == 2 || action == 3) {
         /* Load cursor coordinates */
         ctx->cursor_x = bytestream2_get_le32(&ctx->gbc);
         ctx->cursor_y = bytestream2_get_le32(&ctx->gbc);
 
         /* Load a full cursor sprite */
         if (action == 3) {
             ret = tdsc_load_cursor(avctx);
             /* Do not consider cursor errors fatal unless in explode mode */
             if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
                 return ret;
         }
     } else {
         avpriv_request_sample(avctx, "Cursor action %d", action);
     }
 
     return 0;
 }
 
 static int tdsc_decode_frame(AVCodecContext *avctx, void *data,
                              int *got_frame, AVPacket *avpkt)
 {
     TDSCContext *ctx = avctx->priv_data;
     AVFrame *frame = data;
     int ret, tag_header, keyframe = 0;
     uLongf dlen;
 
     /* Resize deflate buffer on resolution change */
     if (ctx->width != avctx->width || ctx->height != avctx->height) {
         ctx->deflatelen = avctx->width * avctx->height * (3 + 1);
         ret = av_reallocp(&ctx->deflatebuffer, ctx->deflatelen);
         if (ret < 0)
             return ret;
     }
     dlen = ctx->deflatelen;
 
     /* Frames are deflated, need to inflate them first */
     ret = uncompress(ctx->deflatebuffer, &dlen, avpkt->data, avpkt->size);
     if (ret) {
         av_log(avctx, AV_LOG_ERROR, "Deflate error %d.\n", ret);
         return AVERROR_UNKNOWN;
     }
 
     bytestream2_init(&ctx->gbc, ctx->deflatebuffer, dlen);
 
     /* Check for tag and for size info */
     if (bytestream2_get_bytes_left(&ctx->gbc) < 4 + 4) {
         av_log(avctx, AV_LOG_ERROR, "Frame is too small.\n");
         return AVERROR_INVALIDDATA;
     }
 
     /* Read tag */
     tag_header = bytestream2_get_le32(&ctx->gbc);
 
     if (tag_header == MKTAG('T','D','S','F')) {
         int number_tiles;
         if (bytestream2_get_bytes_left(&ctx->gbc) < TDSF_HEADER_SIZE) {
             av_log(avctx, AV_LOG_ERROR, "TDSF tag is too small.\n");
             return AVERROR_INVALIDDATA;
         }
         /* First 4 bytes here are the number of GEPJ/WAR tiles in this frame */
         number_tiles = bytestream2_get_le32(&ctx->gbc);
 
         bytestream2_skip(&ctx->gbc, 4); // internal timestamp maybe?
         keyframe = bytestream2_get_le32(&ctx->gbc) == 0x30;
 
         ret = tdsc_parse_tdsf(avctx, number_tiles);
         if (ret < 0)
             return ret;
 
         /* Check if there is anything else we are able to parse */
         if (bytestream2_get_bytes_left(&ctx->gbc) >= 4 + 4)
             tag_header = bytestream2_get_le32(&ctx->gbc);
     }
 
     /* This tag can be after a TDSF block or on its own frame */
     if (tag_header == MKTAG('D','T','S','M')) {
         /* First 4 bytes here are the total size in bytes for this frame */
         int tag_size = bytestream2_get_le32(&ctx->gbc);
 
         if (bytestream2_get_bytes_left(&ctx->gbc) < tag_size) {
             av_log(avctx, AV_LOG_ERROR, "DTSM tag is too small.\n");
             return AVERROR_INVALIDDATA;
         }
 
         ret = tdsc_parse_dtsm(avctx);
         if (ret < 0)
             return ret;
     }
 
     /* Get the output frame and copy the reference frame */
     ret = ff_get_buffer(avctx, frame, 0);
     if (ret < 0)
         return ret;
 
     ret = av_frame_copy(frame, ctx->refframe);
     if (ret < 0)
         return ret;
 
     /* Paint the cursor on the output frame */
     tdsc_paint_cursor(avctx, frame->data[0], frame->linesize[0]);
 
     /* Frame is ready to be output */
     if (keyframe) {
         frame->pict_type = AV_PICTURE_TYPE_I;
         frame->key_frame = 1;
     } else {
         frame->pict_type = AV_PICTURE_TYPE_P;
     }
     *got_frame = 1;
 

     return avpkt->size;

 }
 
 AVCodec ff_tdsc_decoder = {
     .name           = "tdsc",
     .long_name      = NULL_IF_CONFIG_SMALL("TDSC"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_TDSC,
     .init           = tdsc_init,
     .decode         = tdsc_decode_frame,
     .close          = tdsc_close,
     .priv_data_size = sizeof(TDSCContext),

     .capabilities   = AV_CODEC_CAP_DR1,

     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
                       FF_CODEC_CAP_INIT_CLEANUP,
 };