libavcodec/imm4.c - manifest_repos/ffmpeg - Git at Google

 /*
  * Infinity IMM4 decoder
  *
  * Copyright (c) 2018 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 <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 #include "libavutil/mem_internal.h"
 #include "libavutil/thread.h"

 #include "avcodec.h"
 #include "bswapdsp.h"
 #include "copy_block.h"
 #include "get_bits.h"
 #include "idctdsp.h"
 #include "internal.h"

 #define CBPLO_VLC_BITS   6
 #define CBPHI_VLC_BITS   6
 #define BLKTYPE_VLC_BITS 9
 #define BLOCK_VLC_BITS  12

 typedef struct IMM4Context {
     BswapDSPContext bdsp;
     GetBitContext  gb;

     AVFrame *prev_frame;
     uint8_t *bitstream;
     int bitstream_size;

     int factor;
     unsigned lo;
     unsigned hi;

     ScanTable intra_scantable;
     DECLARE_ALIGNED(32, int16_t, block)[6][64];
     IDCTDSPContext idsp;
 } IMM4Context;

 static const uint8_t intra_cb[] = {
     24, 18, 12
 };

 static const uint8_t inter_cb[] = {
     30, 20, 15
 };

 static const uint8_t cbplo[][2] = {
     {    0,-6 }, { 0x01, 6 }, { 0x02, 6 }, { 0x03, 6 }, { 0x00, 4 },
     { 0x01, 3 }, { 0x02, 3 }, { 0x03, 3 }, { 0x00, 1 },
 };

 static const uint8_t cbphi_bits[] = {
     4, 5, 5, 4, 5, 4, 6, 4, 5, 6, 4, 4, 4, 4, 4, 2
 };

 static const uint8_t cbphi_codes[] = {
     3, 5, 4, 9, 3, 7, 2, 11, 2, 3, 5, 10, 4, 8, 6, 3
 };

 static const uint8_t blktype[][2] = {
     {    0,-8 }, { 0x34, 9 }, {    0,-9 }, { 0x14, 9 }, {    0,-9 },
     { 0x23, 8 }, { 0x13, 8 }, { 0x32, 8 }, { 0x33, 7 }, { 0x22, 7 },
     { 0x12, 7 }, { 0x21, 7 }, { 0x11, 7 }, { 0x04, 6 }, { 0x30, 6 },
     { 0x03, 5 }, { 0x20, 4 }, { 0x10, 4 }, { 0x02, 3 }, { 0x01, 3 },
     { 0x00, 1 },
 };

 static const uint16_t block_symbols[] = {
          0, 0x4082, 0x4003, 0x000B, 0x000A, 0x4E01, 0x4D81, 0x4D01, 0x4C81,
     0x0482, 0x0402, 0x0382, 0x0302, 0x0282, 0x0183, 0x0103, 0x0084, 0x000C,
     0x0085, 0x0B81, 0x0C01, 0x4E81, 0x4F01, 0x4F81, 0x5001, 0x0086, 0x0104,
     0x0203, 0x0283, 0x0303, 0x0502, 0x0C81, 0x0D01, 0x5081, 0x5101, 0x5181,
     0x5201, 0x5281, 0x5301, 0x5381, 0x5401, 0x0000, 0x0009, 0x0008, 0x4C01,
     0x4B81, 0x4B01, 0x4A81, 0x4A01, 0x4981, 0x4901, 0x4881, 0x4002, 0x0B01,
     0x0A81, 0x0A01, 0x0981, 0x0901, 0x0881, 0x0801, 0x0781, 0x0202, 0x0182,
     0x0007, 0x0006, 0x4801, 0x4781, 0x4701, 0x4681, 0x4601, 0x4581, 0x4501,
     0x4481, 0x0701, 0x0681, 0x0102, 0x0083, 0x0005, 0x4401, 0x4381, 0x4301,
     0x4281, 0x0601, 0x0581, 0x0501, 0x0004, 0x4201, 0x4181, 0x4101, 0x4081,
     0x0481, 0x0401, 0x0381, 0x0301, 0x0082, 0x0003, 0x0281, 0x0201, 0x0181,
     0x4001, 0x0001, 0x0081, 0x0101, 0x0002,
 };

 static const uint8_t block_bits[] = {
     -9, 11, 11, 11, 11, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11,
     11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
     12, 12, 12,  7, 10, 10,  9,  9,  9,  9,  9,  9,  9,  9,  9,  9,  9,  9,  9,
      9,  9,  9,  9,  9,  9,  9,  9,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,
      8,  8,  7,  7,  7,  7,  7,  7,  7,  7,  6,  6,  6,  6,  6,  6,  6,  6,  6,
      6,  5,  5,  5,  4,  2,  3,  4,  4,
 };

 static VLC cbplo_tab;
 static VLC cbphi_tab;
 static VLC blktype_tab;
 static VLC block_tab;

 static int get_cbphi(GetBitContext *gb, int x)
 {
     int value;

     value = get_vlc2(gb, cbphi_tab.table, CBPHI_VLC_BITS, 1);
     if (value < 0)
         return AVERROR_INVALIDDATA;

     return x ? value : 15 - value;
 }

 static int decode_block(AVCodecContext *avctx, GetBitContext *gb,
                         int block, int factor, int flag, int offset, int flag2)
 {
     IMM4Context *s = avctx->priv_data;
     const uint8_t *scantable = s->intra_scantable.permutated;
     int i, last, len, factor2;

     for (i = !flag; i < 64; i++) {
         int value;

         value = get_vlc2(gb, block_tab.table, BLOCK_VLC_BITS, 1);
         if (value < 0)
             return AVERROR_INVALIDDATA;
         if (value == 0) {
             last = get_bits1(gb);
             len = get_bits(gb, 6);
             factor2 = get_sbits(gb, 8);
         } else {
             factor2 = value & 0x7F;
             last = (value >> 14) & 1;
             len = (value >> 7) & 0x3F;
             if (get_bits1(gb))
                 factor2 = -factor2;
         }
         i += len;
         if (i >= 64)
             break;
         s->block[block][scantable[i]] = offset * (factor2 < 0 ? -1 : 1) + factor * factor2;
         if (last)
             break;
     }

     if (s->hi == 2 && flag2 && block < 4) {
         if (flag)
             s->block[block][scantable[0]]  *= 2;
         s->block[block][scantable[1]]  *= 2;
         s->block[block][scantable[8]]  *= 2;
         s->block[block][scantable[16]] *= 2;
     }

     return 0;
 }

 static int decode_blocks(AVCodecContext *avctx, GetBitContext *gb,
                          unsigned cbp, int flag, int offset, unsigned flag2)
 {
     IMM4Context *s = avctx->priv_data;
     const uint8_t *scantable = s->intra_scantable.permutated;
     int ret, i;

     memset(s->block, 0, sizeof(s->block));

     for (i = 0; i < 6; i++) {
         if (!flag) {
             int x = get_bits(gb, 8);

             if (x == 255)
                 x = 128;
             x *= 8;

             s->block[i][scantable[0]] = x;
         }

         if (cbp & (1 << (5 - i))) {
             ret = decode_block(avctx, gb, i, s->factor, flag, offset, flag2);
             if (ret < 0)
                 return ret;
         }
     }

     return 0;
 }

 static int decode_intra(AVCodecContext *avctx, GetBitContext *gb, AVFrame *frame)
 {
     IMM4Context *s = avctx->priv_data;
     int ret, x, y, offset = 0;

     if (s->hi == 0) {
         if (s->lo > 2)
             return AVERROR_INVALIDDATA;
         s->factor = intra_cb[s->lo];
     } else {
         s->factor = s->lo * 2;
     }

     if (s->hi) {
         offset = s->factor;
         offset >>= 1;
         if (!(offset & 1))
             offset--;
     }

     for (y = 0; y < avctx->height; y += 16) {
         for (x = 0; x < avctx->width; x += 16) {
             unsigned flag, cbphi, cbplo;

             cbplo = get_vlc2(gb, cbplo_tab.table, CBPLO_VLC_BITS, 1);
             flag = get_bits1(gb);

             cbphi = get_cbphi(gb, 1);

             ret = decode_blocks(avctx, gb, cbplo | (cbphi << 2), 0, offset, flag);
             if (ret < 0)
                 return ret;

             s->idsp.idct_put(frame->data[0] + y * frame->linesize[0] + x,
                              frame->linesize[0], s->block[0]);
             s->idsp.idct_put(frame->data[0] + y * frame->linesize[0] + x + 8,
                              frame->linesize[0], s->block[1]);
             s->idsp.idct_put(frame->data[0] + (y + 8) * frame->linesize[0] + x,
                              frame->linesize[0], s->block[2]);
             s->idsp.idct_put(frame->data[0] + (y + 8) * frame->linesize[0] + x + 8,
                              frame->linesize[0], s->block[3]);
             s->idsp.idct_put(frame->data[1] + (y >> 1) * frame->linesize[1] + (x >> 1),
                              frame->linesize[1], s->block[4]);
             s->idsp.idct_put(frame->data[2] + (y >> 1) * frame->linesize[2] + (x >> 1),
                              frame->linesize[2], s->block[5]);
         }
     }

     return 0;
 }

 static int decode_inter(AVCodecContext *avctx, GetBitContext *gb,
                         AVFrame *frame, AVFrame *prev)
 {
     IMM4Context *s = avctx->priv_data;
     int ret, x, y, offset = 0;

     if (s->hi == 0) {
         if (s->lo > 2)
             return AVERROR_INVALIDDATA;
         s->factor = inter_cb[s->lo];
     } else {
         s->factor = s->lo * 2;
     }

     if (s->hi) {
         offset = s->factor;
         offset >>= 1;
         if (!(offset & 1))
             offset--;
     }

     for (y = 0; y < avctx->height; y += 16) {
         for (x = 0; x < avctx->width; x += 16) {
             int reverse, intra_block, value;
             unsigned cbphi, cbplo, flag2 = 0;

             if (get_bits1(gb)) {
                 copy_block16(frame->data[0] + y * frame->linesize[0] + x,
                              prev->data[0] + y * prev->linesize[0] + x,
                              frame->linesize[0], prev->linesize[0], 16);
                 copy_block8(frame->data[1] + (y >> 1) * frame->linesize[1] + (x >> 1),
                             prev->data[1] + (y >> 1) * prev->linesize[1] + (x >> 1),
                             frame->linesize[1], prev->linesize[1], 8);
                 copy_block8(frame->data[2] + (y >> 1) * frame->linesize[2] + (x >> 1),
                             prev->data[2] + (y >> 1) * prev->linesize[2] + (x >> 1),
                             frame->linesize[2], prev->linesize[2], 8);
                 continue;
             }

             value = get_vlc2(gb, blktype_tab.table, BLKTYPE_VLC_BITS, 1);
             if (value < 0)
                 return AVERROR_INVALIDDATA;

             intra_block = value & 0x07;
             reverse = intra_block == 3;
             if (reverse)
                 flag2 = get_bits1(gb);

             cbplo = value >> 4;
             cbphi = get_cbphi(gb, reverse);
             if (intra_block) {
                 ret = decode_blocks(avctx, gb, cbplo | (cbphi << 2), 0, offset, flag2);
                 if (ret < 0)
                     return ret;

                 s->idsp.idct_put(frame->data[0] + y * frame->linesize[0] + x,
                                  frame->linesize[0], s->block[0]);
                 s->idsp.idct_put(frame->data[0] + y * frame->linesize[0] + x + 8,
                                  frame->linesize[0], s->block[1]);
                 s->idsp.idct_put(frame->data[0] + (y + 8) * frame->linesize[0] + x,
                                  frame->linesize[0], s->block[2]);
                 s->idsp.idct_put(frame->data[0] + (y + 8) * frame->linesize[0] + x + 8,
                                  frame->linesize[0], s->block[3]);
                 s->idsp.idct_put(frame->data[1] + (y >> 1) * frame->linesize[1] + (x >> 1),
                                  frame->linesize[1], s->block[4]);
                 s->idsp.idct_put(frame->data[2] + (y >> 1) * frame->linesize[2] + (x >> 1),
                                  frame->linesize[2], s->block[5]);
             } else {
                 flag2 = get_bits1(gb);
                 skip_bits1(gb);
                 ret = decode_blocks(avctx, gb, cbplo | (cbphi << 2), 1, offset, flag2);
                 if (ret < 0)
                     return ret;

                 copy_block16(frame->data[0] + y * frame->linesize[0] + x,
                              prev->data[0] + y * prev->linesize[0] + x,
                              frame->linesize[0], prev->linesize[0], 16);
                 copy_block8(frame->data[1] + (y >> 1) * frame->linesize[1] + (x >> 1),
                             prev->data[1] + (y >> 1) * prev->linesize[1] + (x >> 1),
                             frame->linesize[1], prev->linesize[1], 8);
                 copy_block8(frame->data[2] + (y >> 1) * frame->linesize[2] + (x >> 1),
                             prev->data[2] + (y >> 1) * prev->linesize[2] + (x >> 1),
                             frame->linesize[2], prev->linesize[2], 8);

                 s->idsp.idct_add(frame->data[0] + y * frame->linesize[0] + x,
                                  frame->linesize[0], s->block[0]);
                 s->idsp.idct_add(frame->data[0] + y * frame->linesize[0] + x + 8,
                                  frame->linesize[0], s->block[1]);
                 s->idsp.idct_add(frame->data[0] + (y + 8) * frame->linesize[0] + x,
                                  frame->linesize[0], s->block[2]);
                 s->idsp.idct_add(frame->data[0] + (y + 8) * frame->linesize[0] + x + 8,
                                  frame->linesize[0], s->block[3]);
                 s->idsp.idct_add(frame->data[1] + (y >> 1) * frame->linesize[1] + (x >> 1),
                                  frame->linesize[1], s->block[4]);
                 s->idsp.idct_add(frame->data[2] + (y >> 1) * frame->linesize[2] + (x >> 1),
                                  frame->linesize[2], s->block[5]);
             }
         }
     }

     return 0;
 }

 static int decode_frame(AVCodecContext *avctx, void *data,
                         int *got_frame, AVPacket *avpkt)
 {
     IMM4Context *s = avctx->priv_data;
     GetBitContext *gb = &s->gb;
     AVFrame *frame = data;
     int width, height;
     unsigned type;
     int ret, scaled;

     if (avpkt->size <= 32)
         return AVERROR_INVALIDDATA;

     av_fast_padded_malloc(&s->bitstream, &s->bitstream_size,
                           FFALIGN(avpkt->size, 4));
     if (!s->bitstream)
         return AVERROR(ENOMEM);

     s->bdsp.bswap_buf((uint32_t *)s->bitstream,
                       (uint32_t *)avpkt->data,
                       (avpkt->size + 3) >> 2);

     if ((ret = init_get_bits8(gb, s->bitstream, FFALIGN(avpkt->size, 4))) < 0)
         return ret;

     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
     avctx->color_range = AVCOL_RANGE_JPEG;

     width = avctx->width;
     height = avctx->height;

     scaled = avpkt->data[8];
     if (scaled < 2) {
         int mode = avpkt->data[10];

         switch (mode) {
         case 1:
             width = 352;
             height = 240;
             break;
         case 2:
             width = 704;
             height = 240;
             break;
         case 4:
             width = 480;
             height = 704;
             break;
         case 17:
             width = 352;
             height = 288;
             break;
         case 18:
             width = 704;
             height = 288;
             break;
         default:
             width = 704;
             height = 576;
             break;
         }
     }

     skip_bits_long(gb, 24 * 8);
     type = get_bits_long(gb, 32);
     s->hi = get_bits(gb, 16);
     s->lo = get_bits(gb, 16);

     switch (type) {
     case 0x19781977:
         frame->key_frame = 1;
         frame->pict_type = AV_PICTURE_TYPE_I;
         break;
     case 0x12250926:
         frame->key_frame = 0;
         frame->pict_type = AV_PICTURE_TYPE_P;
         break;
     default:
         avpriv_request_sample(avctx, "type %X", type);
         return AVERROR_PATCHWELCOME;
     }

     if (avctx->width  != width ||
         avctx->height != height) {
         if (!frame->key_frame) {
             av_log(avctx, AV_LOG_ERROR, "Frame size change is unsupported.\n");
             return AVERROR_INVALIDDATA;
         }
         av_frame_unref(s->prev_frame);
     }

     ret = ff_set_dimensions(avctx, width, height);
     if (ret < 0)
         return ret;

     if ((ret = ff_get_buffer(avctx, frame, frame->key_frame ? AV_GET_BUFFER_FLAG_REF : 0)) < 0)
         return ret;

     if (frame->key_frame) {
         ret = decode_intra(avctx, gb, frame);
         if (ret < 0)
             return ret;

         av_frame_unref(s->prev_frame);
         if ((ret = av_frame_ref(s->prev_frame, frame)) < 0)
             return ret;
     } else {
         if (!s->prev_frame->data[0]) {
             av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
             return AVERROR_INVALIDDATA;
         }

         ret = decode_inter(avctx, gb, frame, s->prev_frame);
         if (ret < 0)
             return ret;
     }

     *got_frame = 1;

     return avpkt->size;
 }

 static av_cold void imm4_init_static_data(void)
 {
     INIT_VLC_STATIC_FROM_LENGTHS(&cbplo_tab, CBPLO_VLC_BITS, FF_ARRAY_ELEMS(cbplo),
                                  &cbplo[0][1], 2, &cbplo[0][0], 2, 1,
                                  0, 0, 1 << CBPLO_VLC_BITS);

     INIT_VLC_SPARSE_STATIC(&cbphi_tab, CBPHI_VLC_BITS, FF_ARRAY_ELEMS(cbphi_bits),
                            cbphi_bits, 1, 1, cbphi_codes, 1, 1, NULL, 0, 0, 64);

     INIT_VLC_STATIC_FROM_LENGTHS(&blktype_tab, BLKTYPE_VLC_BITS, FF_ARRAY_ELEMS(blktype),
                                  &blktype[0][1], 2, &blktype[0][0], 2, 1,
                                  0, 0, 1 << BLKTYPE_VLC_BITS);

     INIT_VLC_STATIC_FROM_LENGTHS(&block_tab, BLOCK_VLC_BITS, FF_ARRAY_ELEMS(block_bits),
                                  block_bits, 1, block_symbols, 2, 2,
                                  0, 0, 1 << BLOCK_VLC_BITS);
 }

 static av_cold int decode_init(AVCodecContext *avctx)
 {
     static AVOnce init_static_once = AV_ONCE_INIT;
     IMM4Context *s = avctx->priv_data;
     uint8_t table[64];

     for (int i = 0; i < 64; i++)
         table[i] = i;

     ff_bswapdsp_init(&s->bdsp);
     ff_idctdsp_init(&s->idsp, avctx);
     ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, table);

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

     ff_thread_once(&init_static_once, imm4_init_static_data);

     return 0;
 }

 static void decode_flush(AVCodecContext *avctx)
 {
     IMM4Context *s = avctx->priv_data;

     av_frame_unref(s->prev_frame);
 }

 static av_cold int decode_close(AVCodecContext *avctx)
 {
     IMM4Context *s = avctx->priv_data;

     av_frame_free(&s->prev_frame);
     av_freep(&s->bitstream);
     s->bitstream_size = 0;

     return 0;
 }

 AVCodec ff_imm4_decoder = {
     .name             = "imm4",
     .long_name        = NULL_IF_CONFIG_SMALL("Infinity IMM4"),
     .type             = AVMEDIA_TYPE_VIDEO,
     .id               = AV_CODEC_ID_IMM4,
     .priv_data_size   = sizeof(IMM4Context),
     .init             = decode_init,
     .close            = decode_close,
     .decode           = decode_frame,
     .flush            = decode_flush,
     .capabilities     = AV_CODEC_CAP_DR1,
     .caps_internal    = FF_CODEC_CAP_INIT_THREADSAFE |
                         FF_CODEC_CAP_INIT_CLEANUP,
 };
	/*
	* Infinity IMM4 decoder
	*
	* Copyright (c) 2018 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 <stdio.h>
	#include <stdlib.h>
	#include <string.h>

	#include "libavutil/mem_internal.h"
	#include "libavutil/thread.h"

	#include "avcodec.h"
	#include "bswapdsp.h"
	#include "copy_block.h"
	#include "get_bits.h"
	#include "idctdsp.h"
	#include "internal.h"

	#define CBPLO_VLC_BITS 6
	#define CBPHI_VLC_BITS 6
	#define BLKTYPE_VLC_BITS 9
	#define BLOCK_VLC_BITS 12

	typedef struct IMM4Context {
	BswapDSPContext bdsp;
	GetBitContext gb;

	AVFrame *prev_frame;
	uint8_t *bitstream;
	int bitstream_size;

	int factor;
	unsigned lo;
	unsigned hi;

	ScanTable intra_scantable;
	DECLARE_ALIGNED(32, int16_t, block)[6][64];
	IDCTDSPContext idsp;
	} IMM4Context;

	static const uint8_t intra_cb[] = {
	24, 18, 12
	};

	static const uint8_t inter_cb[] = {
	30, 20, 15
	};

	static const uint8_t cbplo[][2] = {
	{ 0,-6 }, { 0x01, 6 }, { 0x02, 6 }, { 0x03, 6 }, { 0x00, 4 },
	{ 0x01, 3 }, { 0x02, 3 }, { 0x03, 3 }, { 0x00, 1 },
	};

	static const uint8_t cbphi_bits[] = {
	4, 5, 5, 4, 5, 4, 6, 4, 5, 6, 4, 4, 4, 4, 4, 2
	};

	static const uint8_t cbphi_codes[] = {
	3, 5, 4, 9, 3, 7, 2, 11, 2, 3, 5, 10, 4, 8, 6, 3
	};

	static const uint8_t blktype[][2] = {
	{ 0,-8 }, { 0x34, 9 }, { 0,-9 }, { 0x14, 9 }, { 0,-9 },
	{ 0x23, 8 }, { 0x13, 8 }, { 0x32, 8 }, { 0x33, 7 }, { 0x22, 7 },
	{ 0x12, 7 }, { 0x21, 7 }, { 0x11, 7 }, { 0x04, 6 }, { 0x30, 6 },
	{ 0x03, 5 }, { 0x20, 4 }, { 0x10, 4 }, { 0x02, 3 }, { 0x01, 3 },
	{ 0x00, 1 },
	};

	static const uint16_t block_symbols[] = {
	0, 0x4082, 0x4003, 0x000B, 0x000A, 0x4E01, 0x4D81, 0x4D01, 0x4C81,
	0x0482, 0x0402, 0x0382, 0x0302, 0x0282, 0x0183, 0x0103, 0x0084, 0x000C,
	0x0085, 0x0B81, 0x0C01, 0x4E81, 0x4F01, 0x4F81, 0x5001, 0x0086, 0x0104,
	0x0203, 0x0283, 0x0303, 0x0502, 0x0C81, 0x0D01, 0x5081, 0x5101, 0x5181,
	0x5201, 0x5281, 0x5301, 0x5381, 0x5401, 0x0000, 0x0009, 0x0008, 0x4C01,
	0x4B81, 0x4B01, 0x4A81, 0x4A01, 0x4981, 0x4901, 0x4881, 0x4002, 0x0B01,
	0x0A81, 0x0A01, 0x0981, 0x0901, 0x0881, 0x0801, 0x0781, 0x0202, 0x0182,
	0x0007, 0x0006, 0x4801, 0x4781, 0x4701, 0x4681, 0x4601, 0x4581, 0x4501,
	0x4481, 0x0701, 0x0681, 0x0102, 0x0083, 0x0005, 0x4401, 0x4381, 0x4301,
	0x4281, 0x0601, 0x0581, 0x0501, 0x0004, 0x4201, 0x4181, 0x4101, 0x4081,
	0x0481, 0x0401, 0x0381, 0x0301, 0x0082, 0x0003, 0x0281, 0x0201, 0x0181,
	0x4001, 0x0001, 0x0081, 0x0101, 0x0002,
	};

	static const uint8_t block_bits[] = {
	-9, 11, 11, 11, 11, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11,
	11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
	12, 12, 12, 7, 10, 10, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
	9, 9, 9, 9, 9, 9, 9, 9, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
	8, 8, 7, 7, 7, 7, 7, 7, 7, 7, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	6, 5, 5, 5, 4, 2, 3, 4, 4,
	};

	static VLC cbplo_tab;
	static VLC cbphi_tab;
	static VLC blktype_tab;
	static VLC block_tab;

	static int get_cbphi(GetBitContext *gb, int x)
	{
	int value;

	value = get_vlc2(gb, cbphi_tab.table, CBPHI_VLC_BITS, 1);
	if (value < 0)
	return AVERROR_INVALIDDATA;

	return x ? value : 15 - value;
	}

	static int decode_block(AVCodecContext avctx, GetBitContext gb,
	int block, int factor, int flag, int offset, int flag2)
	{
	IMM4Context *s = avctx->priv_data;
	const uint8_t *scantable = s->intra_scantable.permutated;
	int i, last, len, factor2;

	for (i = !flag; i < 64; i++) {
	int value;

	value = get_vlc2(gb, block_tab.table, BLOCK_VLC_BITS, 1);
	if (value < 0)
	return AVERROR_INVALIDDATA;
	if (value == 0) {
	last = get_bits1(gb);
	len = get_bits(gb, 6);
	factor2 = get_sbits(gb, 8);
	} else {
	factor2 = value & 0x7F;
	last = (value >> 14) & 1;
	len = (value >> 7) & 0x3F;
	if (get_bits1(gb))
	factor2 = -factor2;
	}
	i += len;
	if (i >= 64)
	break;
	s->block[block][scantable[i]] = offset * (factor2 < 0 ? -1 : 1) + factor * factor2;
	if (last)
	break;
	}

	if (s->hi == 2 && flag2 && block < 4) {
	if (flag)
	s->block[block][scantable[0]] *= 2;
	s->block[block][scantable[1]] *= 2;
	s->block[block][scantable[8]] *= 2;
	s->block[block][scantable[16]] *= 2;
	}

	return 0;
	}

	static int decode_blocks(AVCodecContext avctx, GetBitContext gb,
	unsigned cbp, int flag, int offset, unsigned flag2)
	{
	IMM4Context *s = avctx->priv_data;
	const uint8_t *scantable = s->intra_scantable.permutated;
	int ret, i;

	memset(s->block, 0, sizeof(s->block));

	for (i = 0; i < 6; i++) {
	if (!flag) {
	int x = get_bits(gb, 8);

	if (x == 255)
	x = 128;
	x *= 8;

	s->block[i][scantable[0]] = x;
	}

	if (cbp & (1 << (5 - i))) {
	ret = decode_block(avctx, gb, i, s->factor, flag, offset, flag2);
	if (ret < 0)
	return ret;
	}
	}

	return 0;
	}

	static int decode_intra(AVCodecContext avctx, GetBitContext gb, AVFrame *frame)
	{
	IMM4Context *s = avctx->priv_data;
	int ret, x, y, offset = 0;

	if (s->hi == 0) {
	if (s->lo > 2)
	return AVERROR_INVALIDDATA;
	s->factor = intra_cb[s->lo];
	} else {
	s->factor = s->lo * 2;
	}

	if (s->hi) {
	offset = s->factor;
	offset >>= 1;
	if (!(offset & 1))
	offset--;
	}

	for (y = 0; y < avctx->height; y += 16) {
	for (x = 0; x < avctx->width; x += 16) {
	unsigned flag, cbphi, cbplo;

	cbplo = get_vlc2(gb, cbplo_tab.table, CBPLO_VLC_BITS, 1);
	flag = get_bits1(gb);

	cbphi = get_cbphi(gb, 1);

	ret = decode_blocks(avctx, gb, cbplo \| (cbphi << 2), 0, offset, flag);
	if (ret < 0)
	return ret;

	s->idsp.idct_put(frame->data[0] + y * frame->linesize[0] + x,
	frame->linesize[0], s->block[0]);
	s->idsp.idct_put(frame->data[0] + y * frame->linesize[0] + x + 8,
	frame->linesize[0], s->block[1]);
	s->idsp.idct_put(frame->data[0] + (y + 8) * frame->linesize[0] + x,
	frame->linesize[0], s->block[2]);
	s->idsp.idct_put(frame->data[0] + (y + 8) * frame->linesize[0] + x + 8,
	frame->linesize[0], s->block[3]);
	s->idsp.idct_put(frame->data[1] + (y >> 1) * frame->linesize[1] + (x >> 1),
	frame->linesize[1], s->block[4]);
	s->idsp.idct_put(frame->data[2] + (y >> 1) * frame->linesize[2] + (x >> 1),
	frame->linesize[2], s->block[5]);
	}
	}

	return 0;
	}

	static int decode_inter(AVCodecContext avctx, GetBitContext gb,
	AVFrame frame, AVFrame prev)
	{
	IMM4Context *s = avctx->priv_data;
	int ret, x, y, offset = 0;

	if (s->hi == 0) {
	if (s->lo > 2)
	return AVERROR_INVALIDDATA;
	s->factor = inter_cb[s->lo];
	} else {
	s->factor = s->lo * 2;
	}

	if (s->hi) {
	offset = s->factor;
	offset >>= 1;
	if (!(offset & 1))
	offset--;
	}

	for (y = 0; y < avctx->height; y += 16) {
	for (x = 0; x < avctx->width; x += 16) {
	int reverse, intra_block, value;
	unsigned cbphi, cbplo, flag2 = 0;

	if (get_bits1(gb)) {
	copy_block16(frame->data[0] + y * frame->linesize[0] + x,
	prev->data[0] + y * prev->linesize[0] + x,
	frame->linesize[0], prev->linesize[0], 16);
	copy_block8(frame->data[1] + (y >> 1) * frame->linesize[1] + (x >> 1),
	prev->data[1] + (y >> 1) * prev->linesize[1] + (x >> 1),
	frame->linesize[1], prev->linesize[1], 8);
	copy_block8(frame->data[2] + (y >> 1) * frame->linesize[2] + (x >> 1),
	prev->data[2] + (y >> 1) * prev->linesize[2] + (x >> 1),
	frame->linesize[2], prev->linesize[2], 8);
	continue;
	}

	value = get_vlc2(gb, blktype_tab.table, BLKTYPE_VLC_BITS, 1);
	if (value < 0)
	return AVERROR_INVALIDDATA;

	intra_block = value & 0x07;
	reverse = intra_block == 3;
	if (reverse)
	flag2 = get_bits1(gb);

	cbplo = value >> 4;
	cbphi = get_cbphi(gb, reverse);
	if (intra_block) {
	ret = decode_blocks(avctx, gb, cbplo \| (cbphi << 2), 0, offset, flag2);
	if (ret < 0)
	return ret;

	s->idsp.idct_put(frame->data[0] + y * frame->linesize[0] + x,
	frame->linesize[0], s->block[0]);
	s->idsp.idct_put(frame->data[0] + y * frame->linesize[0] + x + 8,
	frame->linesize[0], s->block[1]);
	s->idsp.idct_put(frame->data[0] + (y + 8) * frame->linesize[0] + x,
	frame->linesize[0], s->block[2]);
	s->idsp.idct_put(frame->data[0] + (y + 8) * frame->linesize[0] + x + 8,
	frame->linesize[0], s->block[3]);
	s->idsp.idct_put(frame->data[1] + (y >> 1) * frame->linesize[1] + (x >> 1),
	frame->linesize[1], s->block[4]);
	s->idsp.idct_put(frame->data[2] + (y >> 1) * frame->linesize[2] + (x >> 1),
	frame->linesize[2], s->block[5]);
	} else {
	flag2 = get_bits1(gb);
	skip_bits1(gb);
	ret = decode_blocks(avctx, gb, cbplo \| (cbphi << 2), 1, offset, flag2);
	if (ret < 0)
	return ret;

	copy_block16(frame->data[0] + y * frame->linesize[0] + x,
	prev->data[0] + y * prev->linesize[0] + x,
	frame->linesize[0], prev->linesize[0], 16);
	copy_block8(frame->data[1] + (y >> 1) * frame->linesize[1] + (x >> 1),
	prev->data[1] + (y >> 1) * prev->linesize[1] + (x >> 1),
	frame->linesize[1], prev->linesize[1], 8);
	copy_block8(frame->data[2] + (y >> 1) * frame->linesize[2] + (x >> 1),
	prev->data[2] + (y >> 1) * prev->linesize[2] + (x >> 1),
	frame->linesize[2], prev->linesize[2], 8);

	s->idsp.idct_add(frame->data[0] + y * frame->linesize[0] + x,
	frame->linesize[0], s->block[0]);
	s->idsp.idct_add(frame->data[0] + y * frame->linesize[0] + x + 8,
	frame->linesize[0], s->block[1]);
	s->idsp.idct_add(frame->data[0] + (y + 8) * frame->linesize[0] + x,
	frame->linesize[0], s->block[2]);
	s->idsp.idct_add(frame->data[0] + (y + 8) * frame->linesize[0] + x + 8,
	frame->linesize[0], s->block[3]);
	s->idsp.idct_add(frame->data[1] + (y >> 1) * frame->linesize[1] + (x >> 1),
	frame->linesize[1], s->block[4]);
	s->idsp.idct_add(frame->data[2] + (y >> 1) * frame->linesize[2] + (x >> 1),
	frame->linesize[2], s->block[5]);
	}
	}
	}

	return 0;
	}

	static int decode_frame(AVCodecContext avctx, void data,
	int got_frame, AVPacket avpkt)
	{
	IMM4Context *s = avctx->priv_data;
	GetBitContext *gb = &s->gb;
	AVFrame *frame = data;
	int width, height;
	unsigned type;
	int ret, scaled;

	if (avpkt->size <= 32)
	return AVERROR_INVALIDDATA;

	av_fast_padded_malloc(&s->bitstream, &s->bitstream_size,
	FFALIGN(avpkt->size, 4));
	if (!s->bitstream)
	return AVERROR(ENOMEM);

	s->bdsp.bswap_buf((uint32_t *)s->bitstream,
	(uint32_t *)avpkt->data,
	(avpkt->size + 3) >> 2);

	if ((ret = init_get_bits8(gb, s->bitstream, FFALIGN(avpkt->size, 4))) < 0)
	return ret;

	avctx->pix_fmt = AV_PIX_FMT_YUV420P;
	avctx->color_range = AVCOL_RANGE_JPEG;

	width = avctx->width;
	height = avctx->height;

	scaled = avpkt->data[8];
	if (scaled < 2) {
	int mode = avpkt->data[10];

	switch (mode) {
	case 1:
	width = 352;
	height = 240;
	break;
	case 2:
	width = 704;
	height = 240;
	break;
	case 4:
	width = 480;
	height = 704;
	break;
	case 17:
	width = 352;
	height = 288;
	break;
	case 18:
	width = 704;
	height = 288;
	break;
	default:
	width = 704;
	height = 576;
	break;
	}
	}

	skip_bits_long(gb, 24 * 8);
	type = get_bits_long(gb, 32);
	s->hi = get_bits(gb, 16);
	s->lo = get_bits(gb, 16);

	switch (type) {
	case 0x19781977:
	frame->key_frame = 1;
	frame->pict_type = AV_PICTURE_TYPE_I;
	break;
	case 0x12250926:
	frame->key_frame = 0;
	frame->pict_type = AV_PICTURE_TYPE_P;
	break;
	default:
	avpriv_request_sample(avctx, "type %X", type);
	return AVERROR_PATCHWELCOME;
	}

	if (avctx->width != width \|\|
	avctx->height != height) {
	if (!frame->key_frame) {
	av_log(avctx, AV_LOG_ERROR, "Frame size change is unsupported.\n");
	return AVERROR_INVALIDDATA;
	}
	av_frame_unref(s->prev_frame);
	}

	ret = ff_set_dimensions(avctx, width, height);
	if (ret < 0)
	return ret;

	if ((ret = ff_get_buffer(avctx, frame, frame->key_frame ? AV_GET_BUFFER_FLAG_REF : 0)) < 0)
	return ret;

	if (frame->key_frame) {
	ret = decode_intra(avctx, gb, frame);
	if (ret < 0)
	return ret;

	av_frame_unref(s->prev_frame);
	if ((ret = av_frame_ref(s->prev_frame, frame)) < 0)
	return ret;
	} else {
	if (!s->prev_frame->data[0]) {
	av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
	return AVERROR_INVALIDDATA;
	}

	ret = decode_inter(avctx, gb, frame, s->prev_frame);
	if (ret < 0)
	return ret;
	}

	*got_frame = 1;

	return avpkt->size;
	}

	static av_cold void imm4_init_static_data(void)
	{
	INIT_VLC_STATIC_FROM_LENGTHS(&cbplo_tab, CBPLO_VLC_BITS, FF_ARRAY_ELEMS(cbplo),
	&cbplo[0][1], 2, &cbplo[0][0], 2, 1,
	0, 0, 1 << CBPLO_VLC_BITS);

	INIT_VLC_SPARSE_STATIC(&cbphi_tab, CBPHI_VLC_BITS, FF_ARRAY_ELEMS(cbphi_bits),
	cbphi_bits, 1, 1, cbphi_codes, 1, 1, NULL, 0, 0, 64);

	INIT_VLC_STATIC_FROM_LENGTHS(&blktype_tab, BLKTYPE_VLC_BITS, FF_ARRAY_ELEMS(blktype),
	&blktype[0][1], 2, &blktype[0][0], 2, 1,
	0, 0, 1 << BLKTYPE_VLC_BITS);

	INIT_VLC_STATIC_FROM_LENGTHS(&block_tab, BLOCK_VLC_BITS, FF_ARRAY_ELEMS(block_bits),
	block_bits, 1, block_symbols, 2, 2,
	0, 0, 1 << BLOCK_VLC_BITS);
	}

	static av_cold int decode_init(AVCodecContext *avctx)
	{
	static AVOnce init_static_once = AV_ONCE_INIT;
	IMM4Context *s = avctx->priv_data;
	uint8_t table[64];

	for (int i = 0; i < 64; i++)
	table[i] = i;

	ff_bswapdsp_init(&s->bdsp);
	ff_idctdsp_init(&s->idsp, avctx);
	ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, table);

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

	ff_thread_once(&init_static_once, imm4_init_static_data);

	return 0;
	}

	static void decode_flush(AVCodecContext *avctx)
	{
	IMM4Context *s = avctx->priv_data;

	av_frame_unref(s->prev_frame);
	}

	static av_cold int decode_close(AVCodecContext *avctx)
	{
	IMM4Context *s = avctx->priv_data;

	av_frame_free(&s->prev_frame);
	av_freep(&s->bitstream);
	s->bitstream_size = 0;

	return 0;
	}

	AVCodec ff_imm4_decoder = {
	.name = "imm4",
	.long_name = NULL_IF_CONFIG_SMALL("Infinity IMM4"),
	.type = AVMEDIA_TYPE_VIDEO,
	.id = AV_CODEC_ID_IMM4,
	.priv_data_size = sizeof(IMM4Context),
	.init = decode_init,
	.close = decode_close,
	.decode = decode_frame,
	.flush = decode_flush,
	.capabilities = AV_CODEC_CAP_DR1,
	.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE \|
	FF_CODEC_CAP_INIT_CLEANUP,
	};