/*
  * Quicktime Graphics (SMC) Video Decoder
  * Copyright (C) 2003 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 SMC Video Decoder by Mike Melanson (melanson@pcisys.net)
  * For more information about the SMC format, visit:
  *   http://www.pcisys.net/~melanson/codecs/
  *
  * The SMC decoder outputs PAL8 colorspace data.
  */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 

 #include "libavutil/intreadwrite.h"

 #include "avcodec.h"

 #include "bytestream.h"

 #include "internal.h"

 
 #define CPAIR 2
 #define CQUAD 4
 #define COCTET 8
 
 #define COLORS_PER_TABLE 256
 
 typedef struct SmcContext {
 
     AVCodecContext *avctx;

     AVFrame *frame;

     GetByteContext gb;

 
     /* SMC color tables */
     unsigned char color_pairs[COLORS_PER_TABLE * CPAIR];
     unsigned char color_quads[COLORS_PER_TABLE * CQUAD];
     unsigned char color_octets[COLORS_PER_TABLE * COCTET];
 

     uint32_t pal[256];

 } SmcContext;
 
 #define GET_BLOCK_COUNT() \

   (opcode & 0x10) ? (1 + bytestream2_get_byte(&s->gb)) : 1 + (opcode & 0x0F);

 
 #define ADVANCE_BLOCK() \
 { \
     pixel_ptr += 4; \
     if (pixel_ptr >= width) \
     { \
         pixel_ptr = 0; \
         row_ptr += stride * 4; \
     } \
     total_blocks--; \
     if (total_blocks < 0) \
     { \

         av_log(s->avctx, AV_LOG_INFO, "warning: block counter just went negative (this should not happen)\n"); \

         return; \
     } \
 }
 
 static void smc_decode_stream(SmcContext *s)
 {
     int width = s->avctx->width;
     int height = s->avctx->height;

     int stride = s->frame->linesize[0];

     int i;
     int chunk_size;

     int buf_size = bytestream2_size(&s->gb);

     unsigned char opcode;
     int n_blocks;
     unsigned int color_flags;
     unsigned int color_flags_a;
     unsigned int color_flags_b;
     unsigned int flag_mask;
 

     unsigned char *pixels = s->frame->data[0];

     int image_size = height * s->frame->linesize[0];

     int row_ptr = 0;
     int pixel_ptr = 0;
     int pixel_x, pixel_y;
     int row_inc = stride - 4;
     int block_ptr;
     int prev_block_ptr;
     int prev_block_ptr1, prev_block_ptr2;
     int prev_block_flag;
     int total_blocks;
     int color_table_index;  /* indexes to color pair, quad, or octet tables */
     int pixel;
 
     int color_pair_index = 0;
     int color_quad_index = 0;
     int color_octet_index = 0;
 
     /* make the palette available */

     memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);

     bytestream2_skip(&s->gb, 1);
     chunk_size = bytestream2_get_be24(&s->gb);
     if (chunk_size != buf_size)

         av_log(s->avctx, AV_LOG_INFO, "warning: MOV chunk size != encoded chunk size (%d != %d); using MOV chunk size\n",

             chunk_size, buf_size);

     chunk_size = buf_size;

     total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);

 
     /* traverse through the blocks */
     while (total_blocks) {
         /* sanity checks */
         /* make sure the row pointer hasn't gone wild */
         if (row_ptr >= image_size) {

             av_log(s->avctx, AV_LOG_INFO, "SMC decoder just went out of bounds (row ptr = %d, height = %d)\n",

                 row_ptr, image_size);
             return;
         }
 

         opcode = bytestream2_get_byte(&s->gb);

         switch (opcode & 0xF0) {
         /* skip n blocks */
         case 0x00:
         case 0x10:
             n_blocks = GET_BLOCK_COUNT();
             while (n_blocks--) {
                 ADVANCE_BLOCK();
             }
             break;
 
         /* repeat last block n times */
         case 0x20:
         case 0x30:
             n_blocks = GET_BLOCK_COUNT();
 
             /* sanity check */
             if ((row_ptr == 0) && (pixel_ptr == 0)) {

                 av_log(s->avctx, AV_LOG_INFO, "encountered repeat block opcode (%02X) but no blocks rendered yet\n",

                     opcode & 0xF0);

                 return;

             }
 
             /* figure out where the previous block started */
             if (pixel_ptr == 0)

                 prev_block_ptr1 =

                     (row_ptr - s->avctx->width * 4) + s->avctx->width - 4;
             else
                 prev_block_ptr1 = row_ptr + pixel_ptr - 4;
 
             while (n_blocks--) {
                 block_ptr = row_ptr + pixel_ptr;
                 prev_block_ptr = prev_block_ptr1;
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
                         pixels[block_ptr++] = pixels[prev_block_ptr++];
                     }
                     block_ptr += row_inc;
                     prev_block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         /* repeat previous pair of blocks n times */
         case 0x40:
         case 0x50:
             n_blocks = GET_BLOCK_COUNT();
             n_blocks *= 2;
 
             /* sanity check */
             if ((row_ptr == 0) && (pixel_ptr < 2 * 4)) {

                 av_log(s->avctx, AV_LOG_INFO, "encountered repeat block opcode (%02X) but not enough blocks rendered yet\n",

                     opcode & 0xF0);

                 return;

             }
 
             /* figure out where the previous 2 blocks started */
             if (pixel_ptr == 0)

                 prev_block_ptr1 = (row_ptr - s->avctx->width * 4) +

                     s->avctx->width - 4 * 2;
             else if (pixel_ptr == 4)
                 prev_block_ptr1 = (row_ptr - s->avctx->width * 4) + row_inc;
             else
                 prev_block_ptr1 = row_ptr + pixel_ptr - 4 * 2;
 
             if (pixel_ptr == 0)
                 prev_block_ptr2 = (row_ptr - s->avctx->width * 4) + row_inc;
             else
                 prev_block_ptr2 = row_ptr + pixel_ptr - 4;
 
             prev_block_flag = 0;
             while (n_blocks--) {
                 block_ptr = row_ptr + pixel_ptr;
                 if (prev_block_flag)
                     prev_block_ptr = prev_block_ptr2;
                 else
                     prev_block_ptr = prev_block_ptr1;
                 prev_block_flag = !prev_block_flag;
 
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
                         pixels[block_ptr++] = pixels[prev_block_ptr++];
                     }
                     block_ptr += row_inc;
                     prev_block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         /* 1-color block encoding */
         case 0x60:
         case 0x70:
             n_blocks = GET_BLOCK_COUNT();

             pixel = bytestream2_get_byte(&s->gb);

 
             while (n_blocks--) {
                 block_ptr = row_ptr + pixel_ptr;
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
                         pixels[block_ptr++] = pixel;
                     }
                     block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         /* 2-color block encoding */
         case 0x80:
         case 0x90:
             n_blocks = (opcode & 0x0F) + 1;
 
             /* figure out which color pair to use to paint the 2-color block */
             if ((opcode & 0xF0) == 0x80) {
                 /* fetch the next 2 colors from bytestream and store in next
                  * available entry in the color pair table */
                 for (i = 0; i < CPAIR; i++) {

                     pixel = bytestream2_get_byte(&s->gb);

                     color_table_index = CPAIR * color_pair_index + i;
                     s->color_pairs[color_table_index] = pixel;
                 }
                 /* this is the base index to use for this block */
                 color_table_index = CPAIR * color_pair_index;
                 color_pair_index++;
                 /* wraparound */
                 if (color_pair_index == COLORS_PER_TABLE)
                     color_pair_index = 0;
             } else

                 color_table_index = CPAIR * bytestream2_get_byte(&s->gb);

 
             while (n_blocks--) {

                 color_flags = bytestream2_get_be16(&s->gb);

                 flag_mask = 0x8000;
                 block_ptr = row_ptr + pixel_ptr;
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
                         if (color_flags & flag_mask)
                             pixel = color_table_index + 1;
                         else
                             pixel = color_table_index;
                         flag_mask >>= 1;
                         pixels[block_ptr++] = s->color_pairs[pixel];
                     }
                     block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         /* 4-color block encoding */
         case 0xA0:
         case 0xB0:
             n_blocks = (opcode & 0x0F) + 1;
 
             /* figure out which color quad to use to paint the 4-color block */
             if ((opcode & 0xF0) == 0xA0) {
                 /* fetch the next 4 colors from bytestream and store in next
                  * available entry in the color quad table */
                 for (i = 0; i < CQUAD; i++) {

                     pixel = bytestream2_get_byte(&s->gb);

                     color_table_index = CQUAD * color_quad_index + i;
                     s->color_quads[color_table_index] = pixel;
                 }
                 /* this is the base index to use for this block */
                 color_table_index = CQUAD * color_quad_index;
                 color_quad_index++;
                 /* wraparound */
                 if (color_quad_index == COLORS_PER_TABLE)
                     color_quad_index = 0;
             } else

                 color_table_index = CQUAD * bytestream2_get_byte(&s->gb);

 
             while (n_blocks--) {

                 color_flags = bytestream2_get_be32(&s->gb);

                 /* flag mask actually acts as a bit shift count here */
                 flag_mask = 30;
                 block_ptr = row_ptr + pixel_ptr;
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {

                         pixel = color_table_index +

                             ((color_flags >> flag_mask) & 0x03);
                         flag_mask -= 2;
                         pixels[block_ptr++] = s->color_quads[pixel];
                     }
                     block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         /* 8-color block encoding */
         case 0xC0:
         case 0xD0:
             n_blocks = (opcode & 0x0F) + 1;
 
             /* figure out which color octet to use to paint the 8-color block */
             if ((opcode & 0xF0) == 0xC0) {
                 /* fetch the next 8 colors from bytestream and store in next
                  * available entry in the color octet table */
                 for (i = 0; i < COCTET; i++) {

                     pixel = bytestream2_get_byte(&s->gb);

                     color_table_index = COCTET * color_octet_index + i;
                     s->color_octets[color_table_index] = pixel;
                 }
                 /* this is the base index to use for this block */
                 color_table_index = COCTET * color_octet_index;
                 color_octet_index++;
                 /* wraparound */
                 if (color_octet_index == COLORS_PER_TABLE)
                     color_octet_index = 0;
             } else

                 color_table_index = COCTET * bytestream2_get_byte(&s->gb);

 
             while (n_blocks--) {
                 /*
                   For this input of 6 hex bytes:
                     01 23 45 67 89 AB
                   Mangle it to this output:
                     flags_a = xx012456, flags_b = xx89A37B
                 */
                 /* build the color flags */

                 int val1 = bytestream2_get_be16(&s->gb);
                 int val2 = bytestream2_get_be16(&s->gb);
                 int val3 = bytestream2_get_be16(&s->gb);
                 color_flags_a = ((val1 & 0xFFF0) << 8) | (val2 >> 4);
                 color_flags_b = ((val3 & 0xFFF0) << 8) |
                     ((val1 & 0x0F) << 8) | ((val2 & 0x0F) << 4) | (val3 & 0x0F);

 
                 color_flags = color_flags_a;
                 /* flag mask actually acts as a bit shift count here */
                 flag_mask = 21;
                 block_ptr = row_ptr + pixel_ptr;
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     /* reload flags at third row (iteration pixel_y == 2) */
                     if (pixel_y == 2) {
                         color_flags = color_flags_b;
                         flag_mask = 21;
                     }
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {

                         pixel = color_table_index +

                             ((color_flags >> flag_mask) & 0x07);
                         flag_mask -= 3;
                         pixels[block_ptr++] = s->color_octets[pixel];
                     }
                     block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         /* 16-color block encoding (every pixel is a different color) */
         case 0xE0:
             n_blocks = (opcode & 0x0F) + 1;
 
             while (n_blocks--) {
                 block_ptr = row_ptr + pixel_ptr;
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {

                         pixels[block_ptr++] = bytestream2_get_byte(&s->gb);

                     }
                     block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         case 0xF0:

             avpriv_request_sample(s->avctx, "0xF0 opcode");

             break;
         }
     }

 
     return;

 }
 

 static av_cold int smc_decode_init(AVCodecContext *avctx)

 {

     SmcContext *s = avctx->priv_data;

 
     s->avctx = avctx;

     avctx->pix_fmt = AV_PIX_FMT_PAL8;

     s->frame = av_frame_alloc();
     if (!s->frame)
         return AVERROR(ENOMEM);

 
     return 0;
 }
 
 static int smc_decode_frame(AVCodecContext *avctx,

                              void *data, int *got_frame,

                              AVPacket *avpkt)

 {

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

     SmcContext *s = avctx->priv_data;

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

     int ret;

     bytestream2_init(&s->gb, buf, buf_size);

     if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)

         return ret;

     if (pal) {

         s->frame->palette_has_changed = 1;

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

     smc_decode_stream(s);
 

     *got_frame      = 1;

     if ((ret = av_frame_ref(data, s->frame)) < 0)

         return ret;

 
     /* always report that the buffer was completely consumed */
     return buf_size;
 }
 

 static av_cold int smc_decode_end(AVCodecContext *avctx)

 {

     SmcContext *s = avctx->priv_data;

     av_frame_free(&s->frame);

 
     return 0;
 }
 

 AVCodec ff_smc_decoder = {

     .name           = "smc",

     .long_name      = NULL_IF_CONFIG_SMALL("QuickTime Graphics (SMC)"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_SMC,

     .priv_data_size = sizeof(SmcContext),
     .init           = smc_decode_init,
     .close          = smc_decode_end,
     .decode         = smc_decode_frame,
     .capabilities   = CODEC_CAP_DR1,

 };