/*
  * Quicktime Animation (RLE) Video Decoder
  * Copyright (C) 2004 the ffmpeg project
  *

  * 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

  * QT RLE Video Decoder by Mike Melanson (melanson@pcisys.net)
  * For more information about the QT RLE format, visit:
  *   http://www.pcisys.net/~melanson/codecs/
  *
  * The QT RLE decoder has seven modes of operation:
  * 1, 2, 4, 8, 16, 24, and 32 bits per pixel. For modes 1, 2, 4, and 8

  * the decoder outputs PAL8 colorspace data. 16-bit data yields RGB555

  * data. 24-bit data is RGB24 and 32-bit data is RGB32.

  */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "avcodec.h"

 #include "bytestream.h"

 
 typedef struct QtrleContext {
     AVCodecContext *avctx;
     AVFrame frame;
 

     GetByteContext g;

     uint32_t pal[256];

 } QtrleContext;
 

 #define CHECK_PIXEL_PTR(n)                                                            \
     if ((pixel_ptr + n > pixel_limit) || (pixel_ptr + n < 0)) {                       \

         av_log (s->avctx, AV_LOG_ERROR, "Problem: pixel_ptr = %d, pixel_limit = %d\n",\

                 pixel_ptr + n, pixel_limit);                                          \
         return;                                                                       \
     }                                                                                 \

 static void qtrle_decode_1bpp(QtrleContext *s, int row_ptr, int lines_to_change)

 {

     int rle_code;

     int pixel_ptr;

     int row_inc = s->frame.linesize[0];
     unsigned char pi0, pi1;  /* 2 8-pixel values */
     unsigned char *rgb = s->frame.data[0];
     int pixel_limit = s->frame.linesize[0] * s->avctx->height;
     int skip;

     /* skip & 0x80 appears to mean 'start a new line', which can be interpreted
      * as 'go to next line' during the decoding of a frame but is 'go to first
      * line' at the beginning. Since we always interpret it as 'go to next line'
      * in the decoding loop (which makes code simpler/faster), the first line
      * would not be counted, so we count one more.

      * See: https://trac.ffmpeg.org/ticket/226

      * In the following decoding loop, row_ptr will be the position of the

      * current row. */

     row_ptr  -= row_inc;
     pixel_ptr = row_ptr;
     lines_to_change++;

     while (lines_to_change) {

         skip     =              bytestream2_get_byte(&s->g);
         rle_code = (signed char)bytestream2_get_byte(&s->g);

         if (rle_code == 0)
             break;
         if(skip & 0x80) {
             lines_to_change--;

             row_ptr += row_inc;

             pixel_ptr = row_ptr + 2 * (skip & 0x7f);
         } else
             pixel_ptr += 2 * skip;
         CHECK_PIXEL_PTR(0);  /* make sure pixel_ptr is positive */
 

         if(rle_code == -1)
             continue;
 

         if (rle_code < 0) {
             /* decode the run length code */
             rle_code = -rle_code;
             /* get the next 2 bytes from the stream, treat them as groups
              * of 8 pixels, and output them rle_code times */

 
             pi0 = bytestream2_get_byte(&s->g);
             pi1 = bytestream2_get_byte(&s->g);

             CHECK_PIXEL_PTR(rle_code * 2);
 
             while (rle_code--) {
                 rgb[pixel_ptr++] = pi0;
                 rgb[pixel_ptr++] = pi1;
             }
         } else {
             /* copy the same pixel directly to output 2 times */
             rle_code *= 2;
             CHECK_PIXEL_PTR(rle_code);
 
             while (rle_code--)

                 rgb[pixel_ptr++] = bytestream2_get_byte(&s->g);

         }
     }

 }
 

 static inline void qtrle_decode_2n4bpp(QtrleContext *s, int row_ptr,
                                        int lines_to_change, int bpp)

 {

     int rle_code, i;

     int pixel_ptr;

     int row_inc = s->frame.linesize[0];

     unsigned char pi[16];  /* 16 palette indices */

     unsigned char *rgb = s->frame.data[0];
     int pixel_limit = s->frame.linesize[0] * s->avctx->height;

     int num_pixels = (bpp == 4) ? 8 : 16;

 
     while (lines_to_change--) {

         pixel_ptr = row_ptr + (num_pixels * (bytestream2_get_byte(&s->g) - 1));

         CHECK_PIXEL_PTR(0);

         while ((rle_code = (signed char)bytestream2_get_byte(&s->g)) != -1) {

             if (rle_code == 0) {
                 /* there's another skip code in the stream */

                 pixel_ptr += (num_pixels * (bytestream2_get_byte(&s->g) - 1));

                 CHECK_PIXEL_PTR(0);  /* make sure pixel_ptr is positive */

             } else if (rle_code < 0) {
                 /* decode the run length code */
                 rle_code = -rle_code;
                 /* get the next 4 bytes from the stream, treat them as palette

                  * indexes, and output them rle_code times */

                 for (i = num_pixels-1; i >= 0; i--) {

                     pi[num_pixels-1-i] = (bytestream2_peek_byte(&s->g) >> ((i*bpp) & 0x07)) & ((1<<bpp)-1);
                     bytestream2_skip(&s->g, ((i & ((num_pixels>>2)-1)) == 0));

                 }
                 CHECK_PIXEL_PTR(rle_code * num_pixels);

                 while (rle_code--) {

                     for (i = 0; i < num_pixels; i++)
                         rgb[pixel_ptr++] = pi[i];

                 }
             } else {
                 /* copy the same pixel directly to output 4 times */
                 rle_code *= 4;

                 CHECK_PIXEL_PTR(rle_code*(num_pixels>>2));

                 while (rle_code--) {

                     if(bpp == 4) {

                         int x = bytestream2_get_byte(&s->g);
                         rgb[pixel_ptr++] = (x >> 4) & 0x0f;
                         rgb[pixel_ptr++] =  x       & 0x0f;

                     } else {

                         int x = bytestream2_get_byte(&s->g);
                         rgb[pixel_ptr++] = (x >> 6) & 0x03;
                         rgb[pixel_ptr++] = (x >> 4) & 0x03;
                         rgb[pixel_ptr++] = (x >> 2) & 0x03;
                         rgb[pixel_ptr++] =  x       & 0x03;

                     }

                 }
             }
         }
         row_ptr += row_inc;
     }

 }
 

 static void qtrle_decode_8bpp(QtrleContext *s, int row_ptr, int lines_to_change)

 {

     int rle_code;

     int pixel_ptr;

     int row_inc = s->frame.linesize[0];

     unsigned char pi1, pi2, pi3, pi4;  /* 4 palette indexes */

     unsigned char *rgb = s->frame.data[0];
     int pixel_limit = s->frame.linesize[0] * s->avctx->height;
 
     while (lines_to_change--) {

         pixel_ptr = row_ptr + (4 * (bytestream2_get_byte(&s->g) - 1));

         CHECK_PIXEL_PTR(0);

         while ((rle_code = (signed char)bytestream2_get_byte(&s->g)) != -1) {

             if (rle_code == 0) {
                 /* there's another skip code in the stream */

                 pixel_ptr += (4 * (bytestream2_get_byte(&s->g) - 1));

                 CHECK_PIXEL_PTR(0);  /* make sure pixel_ptr is positive */

             } else if (rle_code < 0) {
                 /* decode the run length code */
                 rle_code = -rle_code;
                 /* get the next 4 bytes from the stream, treat them as palette

                  * indexes, and output them rle_code times */

                 pi1 = bytestream2_get_byte(&s->g);
                 pi2 = bytestream2_get_byte(&s->g);
                 pi3 = bytestream2_get_byte(&s->g);
                 pi4 = bytestream2_get_byte(&s->g);

 
                 CHECK_PIXEL_PTR(rle_code * 4);
 
                 while (rle_code--) {
                     rgb[pixel_ptr++] = pi1;
                     rgb[pixel_ptr++] = pi2;
                     rgb[pixel_ptr++] = pi3;
                     rgb[pixel_ptr++] = pi4;
                 }
             } else {
                 /* copy the same pixel directly to output 4 times */
                 rle_code *= 4;
                 CHECK_PIXEL_PTR(rle_code);
 
                 while (rle_code--) {

                     rgb[pixel_ptr++] = bytestream2_get_byte(&s->g);

                 }
             }
         }
         row_ptr += row_inc;
     }
 }
 

 static void qtrle_decode_16bpp(QtrleContext *s, int row_ptr, int lines_to_change)

 {

     int rle_code;

     int pixel_ptr;

     int row_inc = s->frame.linesize[0];
     unsigned short rgb16;
     unsigned char *rgb = s->frame.data[0];
     int pixel_limit = s->frame.linesize[0] * s->avctx->height;
 
     while (lines_to_change--) {

         pixel_ptr = row_ptr + (bytestream2_get_byte(&s->g) - 1) * 2;

         CHECK_PIXEL_PTR(0);

         while ((rle_code = (signed char)bytestream2_get_byte(&s->g)) != -1) {

             if (rle_code == 0) {
                 /* there's another skip code in the stream */

                 pixel_ptr += (bytestream2_get_byte(&s->g) - 1) * 2;

                 CHECK_PIXEL_PTR(0);  /* make sure pixel_ptr is positive */

             } else if (rle_code < 0) {
                 /* decode the run length code */
                 rle_code = -rle_code;

                 rgb16 = bytestream2_get_be16(&s->g);

 
                 CHECK_PIXEL_PTR(rle_code * 2);
 
                 while (rle_code--) {
                     *(unsigned short *)(&rgb[pixel_ptr]) = rgb16;
                     pixel_ptr += 2;
                 }
             } else {
                 CHECK_PIXEL_PTR(rle_code * 2);
 
                 /* copy pixels directly to output */
                 while (rle_code--) {

                     rgb16 = bytestream2_get_be16(&s->g);

                     *(unsigned short *)(&rgb[pixel_ptr]) = rgb16;
                     pixel_ptr += 2;
                 }
             }
         }
         row_ptr += row_inc;
     }
 }
 

 static void qtrle_decode_24bpp(QtrleContext *s, int row_ptr, int lines_to_change)

 {

     int rle_code;

     int pixel_ptr;

     int row_inc = s->frame.linesize[0];
     unsigned char r, g, b;
     unsigned char *rgb = s->frame.data[0];
     int pixel_limit = s->frame.linesize[0] * s->avctx->height;
 
     while (lines_to_change--) {

         pixel_ptr = row_ptr + (bytestream2_get_byte(&s->g) - 1) * 3;

         CHECK_PIXEL_PTR(0);

         while ((rle_code = (signed char)bytestream2_get_byte(&s->g)) != -1) {

             if (rle_code == 0) {
                 /* there's another skip code in the stream */

                 pixel_ptr += (bytestream2_get_byte(&s->g) - 1) * 3;

                 CHECK_PIXEL_PTR(0);  /* make sure pixel_ptr is positive */

             } else if (rle_code < 0) {
                 /* decode the run length code */
                 rle_code = -rle_code;

                 r = bytestream2_get_byte(&s->g);
                 g = bytestream2_get_byte(&s->g);
                 b = bytestream2_get_byte(&s->g);

 
                 CHECK_PIXEL_PTR(rle_code * 3);
 
                 while (rle_code--) {
                     rgb[pixel_ptr++] = r;
                     rgb[pixel_ptr++] = g;
                     rgb[pixel_ptr++] = b;
                 }
             } else {
                 CHECK_PIXEL_PTR(rle_code * 3);
 
                 /* copy pixels directly to output */
                 while (rle_code--) {

                     rgb[pixel_ptr++] = bytestream2_get_byte(&s->g);
                     rgb[pixel_ptr++] = bytestream2_get_byte(&s->g);
                     rgb[pixel_ptr++] = bytestream2_get_byte(&s->g);

                 }
             }
         }
         row_ptr += row_inc;
     }
 }
 

 static void qtrle_decode_32bpp(QtrleContext *s, int row_ptr, int lines_to_change)

 {

     int rle_code;

     int pixel_ptr;

     int row_inc = s->frame.linesize[0];
     unsigned int argb;
     unsigned char *rgb = s->frame.data[0];
     int pixel_limit = s->frame.linesize[0] * s->avctx->height;
 
     while (lines_to_change--) {

         pixel_ptr = row_ptr + (bytestream2_get_byte(&s->g) - 1) * 4;

         CHECK_PIXEL_PTR(0);

         while ((rle_code = (signed char)bytestream2_get_byte(&s->g)) != -1) {

             if (rle_code == 0) {
                 /* there's another skip code in the stream */

                 pixel_ptr += (bytestream2_get_byte(&s->g) - 1) * 4;

                 CHECK_PIXEL_PTR(0);  /* make sure pixel_ptr is positive */

             } else if (rle_code < 0) {
                 /* decode the run length code */
                 rle_code = -rle_code;

                 argb = bytestream2_get_be32(&s->g);

 
                 CHECK_PIXEL_PTR(rle_code * 4);
 
                 while (rle_code--) {

                     AV_WN32A(rgb + pixel_ptr, argb);

                     pixel_ptr += 4;
                 }
             } else {
                 CHECK_PIXEL_PTR(rle_code * 4);
 
                 /* copy pixels directly to output */
                 while (rle_code--) {

                     argb = bytestream2_get_be32(&s->g);

                     AV_WN32A(rgb + pixel_ptr, argb);
                     pixel_ptr  += 4;

                 }
             }
         }
         row_ptr += row_inc;
     }
 }
 

 static av_cold int qtrle_decode_init(AVCodecContext *avctx)

 {

     QtrleContext *s = avctx->priv_data;

 
     s->avctx = avctx;

     switch (avctx->bits_per_coded_sample) {

     case 1:

     case 33:

         avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;

         break;
 

     case 2:
     case 4:
     case 8:
     case 34:
     case 36:
     case 40:

         avctx->pix_fmt = AV_PIX_FMT_PAL8;

         break;
 
     case 16:

         avctx->pix_fmt = AV_PIX_FMT_RGB555;

         break;
 
     case 24:

         avctx->pix_fmt = AV_PIX_FMT_RGB24;

         break;
 
     case 32:

         avctx->pix_fmt = AV_PIX_FMT_RGB32;

         break;
 
     default:

         av_log (avctx, AV_LOG_ERROR, "Unsupported colorspace: %d bits/sample?\n",

             avctx->bits_per_coded_sample);

         return AVERROR_INVALIDDATA;

     }
 

     avcodec_get_frame_defaults(&s->frame);

     s->frame.data[0] = NULL;
 
     return 0;
 }
 
 static int qtrle_decode_frame(AVCodecContext *avctx,

                               void *data, int *got_frame,

                               AVPacket *avpkt)

 {

     QtrleContext *s = avctx->priv_data;

     int header, start_line;

     int height, row_ptr;

     int has_palette = 0;

     int ret;

     bytestream2_init(&s->g, avpkt->data, avpkt->size);

     s->frame.reference = 3;

     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
                             FF_BUFFER_HINTS_REUSABLE | FF_BUFFER_HINTS_READABLE;

     if ((ret = avctx->reget_buffer(avctx, &s->frame)) < 0) {

         av_log (s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");

         return ret;

     }
 

     /* check if this frame is even supposed to change */

     if (avpkt->size < 8)

         goto done;
 
     /* start after the chunk size */

     bytestream2_seek(&s->g, 4, SEEK_SET);

 
     /* fetch the header */

     header = bytestream2_get_be16(&s->g);

 
     /* if a header is present, fetch additional decoding parameters */
     if (header & 0x0008) {

         if (avpkt->size < 14)

             goto done;

         start_line = bytestream2_get_be16(&s->g);
         bytestream2_skip(&s->g, 2);
         height     = bytestream2_get_be16(&s->g);
         bytestream2_skip(&s->g, 2);

         if (height > s->avctx->height - start_line)
             goto done;

     } else {
         start_line = 0;

         height     = s->avctx->height;

     }
     row_ptr = s->frame.linesize[0] * start_line;
 

     switch (avctx->bits_per_coded_sample) {

     case 1:
     case 33:

         qtrle_decode_1bpp(s, row_ptr, height);

         break;
 
     case 2:
     case 34:

         qtrle_decode_2n4bpp(s, row_ptr, height, 2);

         has_palette = 1;

         break;
 
     case 4:
     case 36:

         qtrle_decode_2n4bpp(s, row_ptr, height, 4);

         has_palette = 1;

         break;
 
     case 8:
     case 40:

         qtrle_decode_8bpp(s, row_ptr, height);

         has_palette = 1;

         break;
 
     case 16:

         qtrle_decode_16bpp(s, row_ptr, height);

         break;
 
     case 24:

         qtrle_decode_24bpp(s, row_ptr, height);

         break;
 
     case 32:

         qtrle_decode_32bpp(s, row_ptr, height);

         break;
 
     default:

         av_log (s->avctx, AV_LOG_ERROR, "Unsupported colorspace: %d bits/sample?\n",

             avctx->bits_per_coded_sample);

         break;
     }

 
     if(has_palette) {

         const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
 
         if (pal) {

             s->frame.palette_has_changed = 1;

             memcpy(s->pal, pal, AVPALETTE_SIZE);

         }

 
         /* make the palette available on the way out */
         memcpy(s->frame.data[1], s->pal, AVPALETTE_SIZE);

     }
 

 done:

     *got_frame      = 1;

     *(AVFrame*)data = s->frame;
 
     /* always report that the buffer was completely consumed */

     return avpkt->size;

 }
 

 static av_cold int qtrle_decode_end(AVCodecContext *avctx)

 {

     QtrleContext *s = avctx->priv_data;

 
     if (s->frame.data[0])
         avctx->release_buffer(avctx, &s->frame);
 
     return 0;
 }
 

 AVCodec ff_qtrle_decoder = {

     .name           = "qtrle",
     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_QTRLE,

     .priv_data_size = sizeof(QtrleContext),
     .init           = qtrle_decode_init,
     .close          = qtrle_decode_end,
     .decode         = qtrle_decode_frame,
     .capabilities   = CODEC_CAP_DR1,

     .long_name      = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),

 };