/*
  * Packed Animation File video and audio decoder
  * Copyright (c) 2012 Paul B Mahol
  *
  * 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
  */
 
 #include "libavutil/intreadwrite.h"
 #include "libavcodec/paf.h"
 #include "bytestream.h"
 #include "avcodec.h"

 #include "copy_block.h"

 #include "internal.h"
 

 
 static const uint8_t block_sequences[16][8] =
 {
     { 0, 0, 0, 0, 0, 0, 0, 0 },
     { 2, 0, 0, 0, 0, 0, 0, 0 },
     { 5, 7, 0, 0, 0, 0, 0, 0 },
     { 5, 0, 0, 0, 0, 0, 0, 0 },
     { 6, 0, 0, 0, 0, 0, 0, 0 },
     { 5, 7, 5, 7, 0, 0, 0, 0 },
     { 5, 7, 5, 0, 0, 0, 0, 0 },
     { 5, 7, 6, 0, 0, 0, 0, 0 },
     { 5, 5, 0, 0, 0, 0, 0, 0 },
     { 3, 0, 0, 0, 0, 0, 0, 0 },
     { 6, 6, 0, 0, 0, 0, 0, 0 },
     { 2, 4, 0, 0, 0, 0, 0, 0 },
     { 2, 4, 5, 7, 0, 0, 0, 0 },
     { 2, 4, 5, 0, 0, 0, 0, 0 },
     { 2, 4, 6, 0, 0, 0, 0, 0 },
     { 2, 4, 5, 7, 5, 7, 0, 0 }
 };
 
 typedef struct PAFVideoDecContext {

     AVFrame  *pic;

     GetByteContext gb;
 
     int     current_frame;
     uint8_t *frame[4];
     int     frame_size;
     int     video_size;
 
     uint8_t *opcodes;
 } PAFVideoDecContext;
 

 static av_cold int paf_vid_close(AVCodecContext *avctx)
 {
     PAFVideoDecContext *c = avctx->priv_data;
     int i;
 
     av_frame_free(&c->pic);
 
     for (i = 0; i < 4; i++)
         av_freep(&c->frame[i]);
 
     return 0;
 }
 

 static av_cold int paf_vid_init(AVCodecContext *avctx)
 {
     PAFVideoDecContext *c = avctx->priv_data;
     int i;
 
     if (avctx->height & 3 || avctx->width & 3) {
         av_log(avctx, AV_LOG_ERROR, "width and height must be multiplies of 4\n");
         return AVERROR_INVALIDDATA;
     }
 

     avctx->pix_fmt = AV_PIX_FMT_PAL8;

     c->pic = av_frame_alloc();
     if (!c->pic)
         return AVERROR(ENOMEM);
 

     c->frame_size = FFALIGN(avctx->height, 256) * avctx->width;
     c->video_size = avctx->height * avctx->width;
     for (i = 0; i < 4; i++) {
         c->frame[i] = av_mallocz(c->frame_size);

         if (!c->frame[i]) {
             paf_vid_close(avctx);

             return AVERROR(ENOMEM);

         }

     }
 
     return 0;
 }
 
 static int get_video_page_offset(AVCodecContext *avctx, uint8_t a, uint8_t b)
 {
     int x, y;
 
     x = b & 0x7F;
     y = ((a & 0x3F) << 1) | (b >> 7 & 1);
 
     return y * 2 * avctx->width + x * 2;
 }
 
 static void copy4h(AVCodecContext *avctx, uint8_t *dst)
 {
     PAFVideoDecContext *c = avctx->priv_data;
     int i;
 
     for (i = 0; i < 4; i++) {
         bytestream2_get_buffer(&c->gb, dst, 4);
         dst += avctx->width;
     }
 }
 
 static void copy_color_mask(AVCodecContext *avctx, uint8_t mask, uint8_t *dst, uint8_t color)
 {
     int i;
 
     for (i = 0; i < 4; i++) {
         if ((mask >> 4) & (1 << (3 - i)))
             dst[i] = color;
         if ((mask & 15) & (1 << (3 - i)))
             dst[avctx->width + i] = color;
     }
 }
 
 static void copy_src_mask(AVCodecContext *avctx, uint8_t mask, uint8_t *dst, const uint8_t *src)
 {
     int i;
 
     for (i = 0; i < 4; i++) {
         if ((mask >> 4) & (1 << (3 - i)))
             dst[i] = src[i];
         if ((mask & 15) & (1 << (3 - i)))
             dst[avctx->width + i] = src[avctx->width + i];
     }
 }
 
 static int decode_0(AVCodecContext *avctx, uint8_t code, uint8_t *pkt)
 {
     PAFVideoDecContext *c = avctx->priv_data;
     uint32_t opcode_size, offset;
     uint8_t *dst, *dend, mask = 0, color = 0, a, b, p;
     const uint8_t *src, *send, *opcodes;
     int  i, j, x = 0;
 
     i = bytestream2_get_byte(&c->gb);
     if (i) {
         if (code & 0x10) {
             int align;
 
             align = bytestream2_tell(&c->gb) & 3;
             if (align)
                 bytestream2_skip(&c->gb, 4 - align);
         }
         do {
             a      = bytestream2_get_byte(&c->gb);
             b      = bytestream2_get_byte(&c->gb);
             p      = (a & 0xC0) >> 6;
             dst    = c->frame[p] + get_video_page_offset(avctx, a, b);
             dend   = c->frame[p] + c->frame_size;
             offset = (b & 0x7F) * 2;
             j      = bytestream2_get_le16(&c->gb) + offset;
 
             do {
                 offset++;
                 if (dst + 3 * avctx->width + 4 > dend)
                     return AVERROR_INVALIDDATA;
                 copy4h(avctx, dst);
                 if ((offset & 0x3F) == 0)
                     dst += avctx->width * 3;
                 dst += 4;
             } while (offset < j);
         } while (--i);
     }
 

     dst  = c->frame[c->current_frame];
     dend = c->frame[c->current_frame] + c->frame_size;

     do {
         a    = bytestream2_get_byte(&c->gb);
         b    = bytestream2_get_byte(&c->gb);
         p    = (a & 0xC0) >> 6;
         src  = c->frame[p] + get_video_page_offset(avctx, a, b);
         send = c->frame[p] + c->frame_size;

         if ((src + 3 * avctx->width + 4 > send) ||
             (dst + 3 * avctx->width + 4 > dend))

             return AVERROR_INVALIDDATA;
         copy_block4(dst, src, avctx->width, avctx->width, 4);
         i++;
         if ((i & 0x3F) == 0)
             dst += avctx->width * 3;
         dst += 4;
     } while (i < c->video_size / 16);
 
     opcode_size = bytestream2_get_le16(&c->gb);
     bytestream2_skip(&c->gb, 2);
 
     if (bytestream2_get_bytes_left(&c->gb) < opcode_size)
         return AVERROR_INVALIDDATA;
 
     opcodes = pkt + bytestream2_tell(&c->gb);
     bytestream2_skipu(&c->gb, opcode_size);
 
     dst = c->frame[c->current_frame];
 
     for (i = 0; i < avctx->height; i += 4, dst += avctx->width * 3) {
         for (j = 0; j < avctx->width; j += 4, dst += 4) {
             int opcode, k = 0;
 
             if (x > opcode_size)
                 return AVERROR_INVALIDDATA;
             if (j & 4) {
                 opcode = opcodes[x] & 15;
                 x++;
             } else {
                 opcode = opcodes[x] >> 4;
             }
 
             while (block_sequences[opcode][k]) {
 
                 offset = avctx->width * 2;
                 code   = block_sequences[opcode][k++];
 
                 switch (code) {
                 case 2:
                     offset = 0;
                 case 3:
                     color  = bytestream2_get_byte(&c->gb);
                 case 4:
                     mask   = bytestream2_get_byte(&c->gb);
                     copy_color_mask(avctx, mask, dst + offset, color);
                     break;
                 case 5:
                     offset = 0;
                 case 6:
                     a    = bytestream2_get_byte(&c->gb);
                     b    = bytestream2_get_byte(&c->gb);
                     p    = (a & 0xC0) >> 6;
                     src  = c->frame[p] + get_video_page_offset(avctx, a, b);
                     send = c->frame[p] + c->frame_size;
                 case 7:
                     if (src + offset + avctx->width + 4 > send)
                         return AVERROR_INVALIDDATA;
                     mask = bytestream2_get_byte(&c->gb);
                     copy_src_mask(avctx, mask, dst + offset, src + offset);
                     break;
                 }
             }
         }
     }
 
     return 0;
 }
 
 static int paf_vid_decode(AVCodecContext *avctx, void *data,

                           int *got_frame, AVPacket *pkt)

 {
     PAFVideoDecContext *c = avctx->priv_data;
     uint8_t code, *dst, *src, *end;
     int i, frame, ret;
 

     if ((ret = ff_reget_buffer(avctx, c->pic)) < 0)

         return ret;
 
     bytestream2_init(&c->gb, pkt->data, pkt->size);
 
     code = bytestream2_get_byte(&c->gb);
     if (code & 0x20) {
         for (i = 0; i < 4; i++)
             memset(c->frame[i], 0, c->frame_size);
 

         memset(c->pic->data[1], 0, AVPALETTE_SIZE);

         c->current_frame = 0;

         c->pic->key_frame = 1;
         c->pic->pict_type = AV_PICTURE_TYPE_I;

     } else {

         c->pic->key_frame = 0;
         c->pic->pict_type = AV_PICTURE_TYPE_P;

     }
 
     if (code & 0x40) {

         uint32_t *out = (uint32_t *)c->pic->data[1];

         int index, count;
 
         index = bytestream2_get_byte(&c->gb);
         count = bytestream2_get_byte(&c->gb) + 1;
 

         if (index + count > 256)

             return AVERROR_INVALIDDATA;

         if (bytestream2_get_bytes_left(&c->gb) < 3*count)

             return AVERROR_INVALIDDATA;
 
         out += index;
         for (i = 0; i < count; i++) {
             unsigned r, g, b;
 
             r = bytestream2_get_byteu(&c->gb);
             r = r << 2 | r >> 4;
             g = bytestream2_get_byteu(&c->gb);
             g = g << 2 | g >> 4;
             b = bytestream2_get_byteu(&c->gb);
             b = b << 2 | b >> 4;
             *out++ = 0xFFU << 24 | r << 16 | g << 8 | b;
         }

         c->pic->palette_has_changed = 1;

     }
 
     switch (code & 0x0F) {
     case 0:
         if ((ret = decode_0(avctx, code, pkt->data)) < 0)
             return ret;
         break;
     case 1:
         dst = c->frame[c->current_frame];
         bytestream2_skip(&c->gb, 2);
         if (bytestream2_get_bytes_left(&c->gb) < c->video_size)
             return AVERROR_INVALIDDATA;
         bytestream2_get_bufferu(&c->gb, dst, c->video_size);
         break;
     case 2:
         frame = bytestream2_get_byte(&c->gb);
         if (frame > 3)
             return AVERROR_INVALIDDATA;
         if (frame != c->current_frame)
             memcpy(c->frame[c->current_frame], c->frame[frame], c->frame_size);
         break;
     case 4:
         dst = c->frame[c->current_frame];
         end = dst + c->video_size;
 
         bytestream2_skip(&c->gb, 2);
 
         while (dst < end) {
             int8_t code;
             int count;
 
             if (bytestream2_get_bytes_left(&c->gb) < 2)
                 return AVERROR_INVALIDDATA;
 
             code  = bytestream2_get_byteu(&c->gb);
             count = FFABS(code) + 1;
 
             if (dst + count > end)
                 return AVERROR_INVALIDDATA;
             if (code < 0)
                 memset(dst, bytestream2_get_byteu(&c->gb), count);
             else
                 bytestream2_get_buffer(&c->gb, dst, count);
             dst += count;
         }
         break;
     default:

         avpriv_request_sample(avctx, "unknown/invalid code");

         return AVERROR_INVALIDDATA;
     }
 

     dst = c->pic->data[0];

     src = c->frame[c->current_frame];
     for (i = 0; i < avctx->height; i++) {
         memcpy(dst, src, avctx->width);

         dst += c->pic->linesize[0];

         src += avctx->width;
     }
 
     c->current_frame = (c->current_frame + 1) & 3;

     if ((ret = av_frame_ref(data, c->pic)) < 0)

         return ret;

     *got_frame       = 1;

 
     return pkt->size;
 }
 
 static av_cold int paf_aud_init(AVCodecContext *avctx)
 {
     if (avctx->channels != 2) {
         av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
         return AVERROR_INVALIDDATA;
     }
 
     avctx->channel_layout = AV_CH_LAYOUT_STEREO;
     avctx->sample_fmt     = AV_SAMPLE_FMT_S16;
 
     return 0;
 }
 
 static int paf_aud_decode(AVCodecContext *avctx, void *data,
                           int *got_frame_ptr, AVPacket *pkt)
 {

     AVFrame *frame = data;

     uint8_t *buf = pkt->data;
     int16_t *output_samples;
     const uint8_t *t;
     int frames, ret, i, j, k;
 
     frames = pkt->size / PAF_SOUND_FRAME_SIZE;
     if (frames < 1)
         return AVERROR_INVALIDDATA;
 

     frame->nb_samples = PAF_SOUND_SAMPLES * frames;

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

         return ret;
 

     output_samples = (int16_t *)frame->data[0];

     for (i = 0; i < frames; i++) {
         t = buf + 256 * sizeof(uint16_t);
         for (j = 0; j < PAF_SOUND_SAMPLES; j++) {
             for (k = 0; k < 2; k++) {

                 *output_samples++ = AV_RL16(buf + *t * 2);
                 t++;

             }
         }
         buf += PAF_SOUND_FRAME_SIZE;
     }
 
     *got_frame_ptr   = 1;
 
     return pkt->size;
 }
 
 AVCodec ff_paf_video_decoder = {
     .name           = "paf_video",

     .long_name      = NULL_IF_CONFIG_SMALL("Amazing Studio Packed Animation File Video"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_PAF_VIDEO,

     .priv_data_size = sizeof(PAFVideoDecContext),
     .init           = paf_vid_init,
     .close          = paf_vid_close,
     .decode         = paf_vid_decode,

     .capabilities   = CODEC_CAP_DR1,

 };
 
 AVCodec ff_paf_audio_decoder = {
     .name           = "paf_audio",

     .long_name      = NULL_IF_CONFIG_SMALL("Amazing Studio Packed Animation File Audio"),

     .type           = AVMEDIA_TYPE_AUDIO,

     .id             = AV_CODEC_ID_PAF_AUDIO,

     .init           = paf_aud_init,
     .decode         = paf_aud_decode,
     .capabilities   = CODEC_CAP_DR1,
 };