/*

 * FLI/FLC Animation Video Decoder

 * Copyright (C) 2003, 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

 * Autodesk Animator FLI/FLC Video Decoder

 * by Mike Melanson (melanson@pcisys.net)

 * for more information on the .fli/.flc file format and all of its many

 * variations, visit:

 *   http://www.compuphase.com/flic.htm

 *

 * This decoder outputs PAL8/RGB555/RGB565/BGR24. To use this decoder, be

 * sure that your demuxer sends the FLI file header to the decoder via

 * the extradata chunk in AVCodecContext. The chunk should be 128 bytes

 * large. The only exception is for FLI files from the game "Magic Carpet",

 * in which the header is only 12 bytes.

 */

#include <string.h>

#include "libavutil/intreadwrite.h"

#include "avcodec.h"

#include "bytestream.h"

#include "codec_internal.h"

#include "decode.h"

#include "mathops.h"

#define FLI_256_COLOR 4

#define FLI_DELTA     7

#define FLI_COLOR     11

#define FLI_LC        12

#define FLI_BLACK     13

#define FLI_BRUN      15

#define FLI_COPY      16

#define FLI_MINI      18

#define FLI_DTA_BRUN  25

#define FLI_DTA_COPY  26

#define FLI_DTA_LC    27

#define FLI_TYPE_CODE     (0xAF11)

#define FLC_FLX_TYPE_CODE (0xAF12)

#define FLC_DTA_TYPE_CODE (0xAF44) /* Marks an "Extended FLC" comes from Dave's Targa Animator (DTA) */

#define FLC_MAGIC_CARPET_SYNTHETIC_TYPE_CODE (0xAF13)

static inline int check_pixel_ptr(ptrdiff_t ptr, int n,

                                  ptrdiff_t limit, int direction)

{

    if (( direction && ptr + n > limit) ||

        (!direction && ptr + n < limit))

        return AVERROR_INVALIDDATA;

    return 0;

}

#define CHECK_PIXEL_PTR(n) \

{ \

    ret = check_pixel_ptr(pixel_ptr, (n), pixel_limit, direction); \

    if (ret < 0) \

        return ret; \

}

#define CHECK_Y_PTR() \

{ \

    ret = check_pixel_ptr(y_ptr, 0, pixel_limit, direction); \

    if (ret < 0) \

        return ret; \

}

typedef struct FlicDecodeContext {

    AVCodecContext *avctx;

    AVFrame *frame;

    unsigned int palette[256];

    int new_palette;

    int fli_type;  /* either 0xAF11 or 0xAF12, affects palette resolution */

} FlicDecodeContext;

static av_cold int flic_decode_init(AVCodecContext *avctx)

{

    FlicDecodeContext *s = avctx->priv_data;

    uint8_t *fli_header = avctx->extradata;

    int depth;

    if (avctx->extradata_size != 0 &&

        avctx->extradata_size != 12 &&

        avctx->extradata_size != 128 &&

        avctx->extradata_size != 256 &&

        avctx->extradata_size != 904 &&

        avctx->extradata_size != 1024) {

        av_log(avctx, AV_LOG_ERROR, "Unexpected extradata size %d\n", avctx->extradata_size);

        return AVERROR_INVALIDDATA;

    }

    s->avctx = avctx;

    if (s->avctx->extradata_size == 12) {

        /* special case for magic carpet FLIs */

        s->fli_type = FLC_MAGIC_CARPET_SYNTHETIC_TYPE_CODE;

        depth = 8;

    } else if (avctx->extradata_size == 1024) {

        uint8_t *ptr = avctx->extradata;

        int i;

        for (i = 0; i < 256; i++) {

            s->palette[i] = AV_RL32(ptr);

            ptr += 4;

        }

        depth = 8;

        /* FLI in MOV, see e.g. FFmpeg trac issue #626 */

    } else if (avctx->extradata_size == 0 ||

               avctx->extradata_size == 256 ||

        /* see FFmpeg ticket #1234 */

               avctx->extradata_size == 904) {

        s->fli_type = FLI_TYPE_CODE;

        depth = 8;

    } else {

        s->fli_type = AV_RL16(&fli_header[4]);

        depth = AV_RL16(&fli_header[12]);

    }

    if (depth == 0) {

        depth = 8; /* Some FLC generators set depth to zero, when they mean 8Bpp. Fix up here */

    }

    if ((s->fli_type == FLC_FLX_TYPE_CODE) && (depth == 16)) {

        depth = 15; /* Original Autodesk FLX's say the depth is 16Bpp when it is really 15Bpp */

    }

    switch (depth) {

        case 1  : avctx->pix_fmt = AV_PIX_FMT_MONOBLACK; break;

        case 8  : avctx->pix_fmt = AV_PIX_FMT_PAL8; break;

        case 15 : avctx->pix_fmt = AV_PIX_FMT_RGB555; break;

        case 16 : avctx->pix_fmt = AV_PIX_FMT_RGB565; break;

        case 24 : avctx->pix_fmt = AV_PIX_FMT_BGR24; break;

        default :

                  av_log(avctx, AV_LOG_ERROR, "Unknown FLC/FLX depth of %d Bpp is unsupported.\n",depth);

                  return AVERROR_INVALIDDATA;

    }

    s->frame = av_frame_alloc();

    if (!s->frame)

        return AVERROR(ENOMEM);

    s->new_palette = 0;

    return 0;

}

static int flic_decode_frame_1BPP(AVCodecContext *avctx,

                                  AVFrame *rframe, int *got_frame,

                                  const uint8_t *buf, int buf_size)

{

    FlicDecodeContext *s = avctx->priv_data;

    GetByteContext g2;

    ptrdiff_t pixel_ptr;

    unsigned int frame_size;

    int num_chunks;

    unsigned int chunk_size;

    int chunk_type;

    int i, j, ret, direction;

    int lines;

    int compressed_lines;

    int starting_line;

    int line_packets;

    ptrdiff_t y_ptr;

    int byte_run;

    int pixel_skip;

    int pixel_countdown;

    unsigned char *pixels;

    ptrdiff_t pixel_limit;

    bytestream2_init(&g2, buf, buf_size);

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

        return ret;

    direction = s->frame->linesize[0] > 0;

    pixels = s->frame->data[0];

    pixel_limit = s->avctx->height * s->frame->linesize[0];

    if (buf_size < 16 || buf_size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE)

        return AVERROR_INVALIDDATA;

    frame_size = bytestream2_get_le32(&g2);

    if (frame_size > buf_size)

        frame_size = buf_size;

    bytestream2_skip(&g2, 2); /* skip the magic number */

    num_chunks = bytestream2_get_le16(&g2);

    bytestream2_skip(&g2, 8);  /* skip padding */

    if (frame_size < 16)

        return AVERROR_INVALIDDATA;

    frame_size -= 16;

    /* iterate through the chunks */

    while ((frame_size >= 6) && (num_chunks > 0) &&

            bytestream2_get_bytes_left(&g2) >= 4) {

        int stream_ptr_after_chunk;

        chunk_size = bytestream2_get_le32(&g2);

        if (chunk_size > frame_size) {

            av_log(avctx, AV_LOG_WARNING,

                   "Invalid chunk_size = %u > frame_size = %u\n", chunk_size, frame_size);

            chunk_size = frame_size;

        }

        stream_ptr_after_chunk = bytestream2_tell(&g2) - 4 + chunk_size;

        chunk_type = bytestream2_get_le16(&g2);

        switch (chunk_type) {

        case FLI_BRUN:

            /* Byte run compression: This chunk type only occurs in the first

             * FLI frame and it will update the entire frame. */

            y_ptr = 0;

            for (lines = 0; lines < s->avctx->height; lines++) {

                pixel_ptr = y_ptr;

                /* disregard the line packets; instead, iterate through all

                 * pixels on a row */

                bytestream2_skip(&g2, 1);

                pixel_countdown = (s->avctx->width + 7) >> 3;

                while (pixel_countdown > 0) {

                    if (bytestream2_tell(&g2) + 1 > stream_ptr_after_chunk)

                        break;

                    byte_run = sign_extend(bytestream2_get_byte(&g2), 8);

                    if (!byte_run) {

                        av_log(avctx, AV_LOG_ERROR, "Invalid byte run value.\n");

                        return AVERROR_INVALIDDATA;

                    }

                    if (byte_run > 0) {

                        int value = bytestream2_get_byte(&g2);

                        CHECK_PIXEL_PTR(byte_run);

                        for (j = 0; j < byte_run; j++) {

                            pixels[pixel_ptr++] = value;

                            pixel_countdown--;

                            if (pixel_countdown < 0)

                                av_log(avctx, AV_LOG_ERROR, "pixel_countdown < 0 (%d) at line %d\n",

                                       pixel_countdown, lines);

                        }

                    } else {  /* copy bytes if byte_run < 0 */

                        byte_run = -byte_run;

                        CHECK_PIXEL_PTR(byte_run);

                        if (bytestream2_tell(&g2) + byte_run > stream_ptr_after_chunk)

                            break;

                        for (j = 0; j < byte_run; j++) {

                            pixels[pixel_ptr++] = bytestream2_get_byte(&g2);

                            pixel_countdown--;

                            if (pixel_countdown < 0)

                                av_log(avctx, AV_LOG_ERROR, "pixel_countdown < 0 (%d) at line %d\n",

                                       pixel_countdown, lines);

                        }

                    }

                }

                y_ptr += s->frame->linesize[0];

            }

            break;

        case FLI_LC:

            /* line compressed */

            starting_line = bytestream2_get_le16(&g2);

            if (starting_line >= s->avctx->height)

                return AVERROR_INVALIDDATA;

            y_ptr = 0;

            y_ptr += starting_line * s->frame->linesize[0];

            compressed_lines = bytestream2_get_le16(&g2);

            while (compressed_lines > 0) {

                pixel_ptr = y_ptr;

                CHECK_PIXEL_PTR(0);

                pixel_countdown = (s->avctx->width + 7) >> 3;

                if (bytestream2_tell(&g2) + 1 > stream_ptr_after_chunk)

                    break;

                line_packets = bytestream2_get_byte(&g2);

                if (line_packets > 0) {

                    for (i = 0; i < line_packets; i++) {

                        /* account for the skip bytes */

                        if (bytestream2_tell(&g2) + 1 > stream_ptr_after_chunk)

                            break;

                        pixel_skip = bytestream2_get_byte(&g2);

                        pixel_ptr += pixel_skip;

                        pixel_countdown -= pixel_skip;

                        byte_run = sign_extend(bytestream2_get_byte(&g2),8);

                        if (byte_run > 0) {

                            CHECK_PIXEL_PTR(byte_run);

                            if (bytestream2_tell(&g2) + byte_run > stream_ptr_after_chunk)

                                break;

                            for (j = 0; j < byte_run; j++, pixel_countdown--) {

                                pixels[pixel_ptr++] = bytestream2_get_byte(&g2);

                            }

                        } else if (byte_run < 0) {

                            int value = bytestream2_get_byte(&g2);

                            byte_run = -byte_run;

                            CHECK_PIXEL_PTR(byte_run);

                            for (j = 0; j < byte_run; j++, pixel_countdown--) {

                                pixels[pixel_ptr++] = value;

                            }

                        }

                    }

                }

                y_ptr += s->frame->linesize[0];

                compressed_lines--;

            }

            break;

        default:

            av_log(avctx, AV_LOG_ERROR, "Unrecognized chunk type: %d\n", chunk_type);

            break;

        }

        if (stream_ptr_after_chunk - bytestream2_tell(&g2) >= 0) {

            bytestream2_skip(&g2, stream_ptr_after_chunk - bytestream2_tell(&g2));

        } else {

            av_log(avctx, AV_LOG_ERROR, "Chunk overread\n");

            break;

        }

        frame_size -= chunk_size;

        num_chunks--;

    }

    /* by the end of the chunk, the stream ptr should equal the frame

     * size (minus 1 or 2, possibly); if it doesn't, issue a warning */

    if (bytestream2_get_bytes_left(&g2) > 2)

        av_log(avctx, AV_LOG_ERROR, "Processed FLI chunk where chunk size = %d " \

               "and final chunk ptr = %d\n", buf_size,

               buf_size - bytestream2_get_bytes_left(&g2));

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

        return ret;

    *got_frame = 1;

    return buf_size;

}

static int flic_decode_frame_8BPP(AVCodecContext *avctx,

                                  AVFrame *rframe, int *got_frame,

                                  const uint8_t *buf, int buf_size)

{

    FlicDecodeContext *s = avctx->priv_data;

    GetByteContext g2;

    ptrdiff_t pixel_ptr;

    int palette_ptr;

    unsigned char palette_idx1;

    unsigned char palette_idx2;

    unsigned int frame_size;

    int num_chunks;

    unsigned int chunk_size;

    int chunk_type;

    int i, j, ret, direction;

    int color_packets;

    int color_changes;

    int color_shift;

    unsigned char r, g, b;

    int lines;

    int compressed_lines;

    int starting_line;

    int line_packets;

    ptrdiff_t y_ptr;

    int byte_run;

    int pixel_skip;

    int pixel_countdown;

    unsigned char *pixels;

    ptrdiff_t pixel_limit;

    bytestream2_init(&g2, buf, buf_size);

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

        return ret;

    direction = s->frame->linesize[0] > 0;

    pixels = s->frame->data[0];

    pixel_limit = s->avctx->height * s->frame->linesize[0];

    if (buf_size < 16 || buf_size > INT_MAX - (3 * 256 + AV_INPUT_BUFFER_PADDING_SIZE))

        return AVERROR_INVALIDDATA;

    frame_size = bytestream2_get_le32(&g2);

    if (frame_size > buf_size)

        frame_size = buf_size;

    bytestream2_skip(&g2, 2); /* skip the magic number */

    num_chunks = bytestream2_get_le16(&g2);

    bytestream2_skip(&g2, 8);  /* skip padding */

    if (frame_size < 16)

        return AVERROR_INVALIDDATA;

    frame_size -= 16;

    /* iterate through the chunks */

    while ((frame_size >= 6) && (num_chunks > 0) &&

            bytestream2_get_bytes_left(&g2) >= 4) {

        int stream_ptr_after_chunk;

        chunk_size = bytestream2_get_le32(&g2);

        if (chunk_size > frame_size) {

            av_log(avctx, AV_LOG_WARNING,

                   "Invalid chunk_size = %u > frame_size = %u\n", chunk_size, frame_size);

            chunk_size = frame_size;

        }

        stream_ptr_after_chunk = bytestream2_tell(&g2) - 4 + chunk_size;

        chunk_type = bytestream2_get_le16(&g2);

        switch (chunk_type) {

        case FLI_256_COLOR:

        case FLI_COLOR:

            /* check special case: If this file is from the Magic Carpet

             * game and uses 6-bit colors even though it reports 256-color

             * chunks in a 0xAF12-type file (fli_type is set to 0xAF13 during

             * initialization) */

            if ((chunk_type == FLI_256_COLOR) && (s->fli_type != FLC_MAGIC_CARPET_SYNTHETIC_TYPE_CODE))

                color_shift = 0;

            else

                color_shift = 2;

            /* set up the palette */

            color_packets = bytestream2_get_le16(&g2);

            palette_ptr = 0;

            for (i = 0; i < color_packets; i++) {

                /* first byte is how many colors to skip */

                palette_ptr += bytestream2_get_byte(&g2);

                /* next byte indicates how many entries to change */

                color_changes = bytestream2_get_byte(&g2);

                /* if there are 0 color changes, there are actually 256 */

                if (color_changes == 0)

                    color_changes = 256;

                if (bytestream2_tell(&g2) + color_changes * 3 > stream_ptr_after_chunk)

                    break;

                for (j = 0; j < color_changes; j++) {

                    unsigned int entry;

                    /* wrap around, for good measure */

                    if ((unsigned)palette_ptr >= 256)

                        palette_ptr = 0;

                    r = bytestream2_get_byte(&g2) << color_shift;

                    g = bytestream2_get_byte(&g2) << color_shift;

                    b = bytestream2_get_byte(&g2) << color_shift;

                    entry = 0xFFU << 24 | r << 16 | g << 8 | b;

                    if (color_shift == 2)

                        entry |= entry >> 6 & 0x30303;

                    if (s->palette[palette_ptr] != entry)

                        s->new_palette = 1;

                    s->palette[palette_ptr++] = entry;

                }

            }

            break;

        case FLI_DELTA:

            y_ptr = 0;

            compressed_lines = bytestream2_get_le16(&g2);

            while (compressed_lines > 0) {

                if (bytestream2_tell(&g2) + 2 > stream_ptr_after_chunk)

                    break;

                CHECK_Y_PTR()

                line_packets = sign_extend(bytestream2_get_le16(&g2), 16);

                if ((line_packets & 0xC000) == 0xC000) {

                    // line skip opcode

                    line_packets = -line_packets;

                    if (line_packets > s->avctx->height)

                        return AVERROR_INVALIDDATA;

                    y_ptr += line_packets * s->frame->linesize[0];

                } else if ((line_packets & 0xC000) == 0x4000) {

                    av_log(avctx, AV_LOG_ERROR, "Undefined opcode (%x) in DELTA_FLI\n", line_packets);

                } else if ((line_packets & 0xC000) == 0x8000) {

                    // "last byte" opcode

                    pixel_ptr= y_ptr + s->frame->linesize[0] - 1;

                    CHECK_PIXEL_PTR(0);

                    pixels[pixel_ptr] = line_packets & 0xff;

                } else {

                    compressed_lines--;

                    pixel_ptr = y_ptr;

                    CHECK_PIXEL_PTR(0);

                    pixel_countdown = s->avctx->width;

                    for (i = 0; i < line_packets; i++) {

                        if (bytestream2_tell(&g2) + 2 > stream_ptr_after_chunk)

                            break;

                        /* account for the skip bytes */

                        pixel_skip = bytestream2_get_byte(&g2);

                        pixel_ptr += pixel_skip;

                        pixel_countdown -= pixel_skip;

                        byte_run = sign_extend(bytestream2_get_byte(&g2), 8);

                        if (byte_run < 0) {

                            byte_run = -byte_run;

                            palette_idx1 = bytestream2_get_byte(&g2);

                            palette_idx2 = bytestream2_get_byte(&g2);

                            CHECK_PIXEL_PTR(byte_run * 2);

                            for (j = 0; j < byte_run; j++, pixel_countdown -= 2) {

                                pixels[pixel_ptr++] = palette_idx1;

                                pixels[pixel_ptr++] = palette_idx2;

                            }

                        } else {

                            CHECK_PIXEL_PTR(byte_run * 2);

                            if (bytestream2_tell(&g2) + byte_run * 2 > stream_ptr_after_chunk)

                                break;

                            for (j = 0; j < byte_run * 2; j++, pixel_countdown--) {

                                pixels[pixel_ptr++] = bytestream2_get_byte(&g2);

                            }

                        }

                    }

                    y_ptr += s->frame->linesize[0];

                }

            }

            break;

        case FLI_LC:

            /* line compressed */

            starting_line = bytestream2_get_le16(&g2);

            if (starting_line >= s->avctx->height)

                return AVERROR_INVALIDDATA;

            y_ptr = 0;

            y_ptr += starting_line * s->frame->linesize[0];

            compressed_lines = bytestream2_get_le16(&g2);

            while (compressed_lines > 0) {

                pixel_ptr = y_ptr;

                CHECK_PIXEL_PTR(0);

                pixel_countdown = s->avctx->width;

                if (bytestream2_tell(&g2) + 1 > stream_ptr_after_chunk)

                    break;

                line_packets = bytestream2_get_byte(&g2);

                if (line_packets > 0) {

                    for (i = 0; i < line_packets; i++) {

                        /* account for the skip bytes */

                        if (bytestream2_tell(&g2) + 1 > stream_ptr_after_chunk)

                            break;

                        pixel_skip = bytestream2_get_byte(&g2);

                        pixel_ptr += pixel_skip;

                        pixel_countdown -= pixel_skip;

                        byte_run = sign_extend(bytestream2_get_byte(&g2),8);

                        if (byte_run > 0) {

                            CHECK_PIXEL_PTR(byte_run);

                            if (bytestream2_tell(&g2) + byte_run > stream_ptr_after_chunk)

                                break;

                            for (j = 0; j < byte_run; j++, pixel_countdown--) {

                                pixels[pixel_ptr++] = bytestream2_get_byte(&g2);

                            }

                        } else if (byte_run < 0) {

                            byte_run = -byte_run;

                            palette_idx1 = bytestream2_get_byte(&g2);

                            CHECK_PIXEL_PTR(byte_run);

                            for (j = 0; j < byte_run; j++, pixel_countdown--) {

                                pixels[pixel_ptr++] = palette_idx1;

                            }

                        }

                    }

                }

                y_ptr += s->frame->linesize[0];

                compressed_lines--;

            }

            break;

        case FLI_BLACK:

            /* set the whole frame to color 0 (which is usually black) */

            for (int y = 0; y < s->avctx->height; y++)

                memset(pixels + y * s->frame->linesize[0], 0, s->avctx->width);

            break;

        case FLI_BRUN:

            /* Byte run compression: This chunk type only occurs in the first

             * FLI frame and it will update the entire frame. */

            y_ptr = 0;

            for (lines = 0; lines < s->avctx->height; lines++) {

                pixel_ptr = y_ptr;

                /* disregard the line packets; instead, iterate through all

                 * pixels on a row */

                 bytestream2_skip(&g2, 1);

                pixel_countdown = s->avctx->width;

                while (pixel_countdown > 0) {

                    if (bytestream2_tell(&g2) + 1 > stream_ptr_after_chunk)

                        break;

                    byte_run = sign_extend(bytestream2_get_byte(&g2), 8);

                    if (!byte_run) {

                        av_log(avctx, AV_LOG_ERROR, "Invalid byte run value.\n");

                        return AVERROR_INVALIDDATA;

                    }

                    if (byte_run > 0) {

                        palette_idx1 = bytestream2_get_byte(&g2);

                        CHECK_PIXEL_PTR(byte_run);

                        for (j = 0; j < byte_run; j++) {

                            pixels[pixel_ptr++] = palette_idx1;

                            pixel_countdown--;

                            if (pixel_countdown < 0)

                                av_log(avctx, AV_LOG_ERROR, "pixel_countdown < 0 (%d) at line %d\n",

                                       pixel_countdown, lines);

                        }

                    } else {  /* copy bytes if byte_run < 0 */

                        byte_run = -byte_run;

                        CHECK_PIXEL_PTR(byte_run);

                        if (bytestream2_tell(&g2) + byte_run > stream_ptr_after_chunk)

                            break;

                        for (j = 0; j < byte_run; j++) {

                            pixels[pixel_ptr++] = bytestream2_get_byte(&g2);

                            pixel_countdown--;

                            if (pixel_countdown < 0)

                                av_log(avctx, AV_LOG_ERROR, "pixel_countdown < 0 (%d) at line %d\n",

                                       pixel_countdown, lines);

                        }

                    }

                }

                y_ptr += s->frame->linesize[0];

            }

            break;

        case FLI_COPY:

            /* copy the chunk (uncompressed frame) */

            if (chunk_size - 6 != FFALIGN(s->avctx->width, 4) * s->avctx->height) {

                av_log(avctx, AV_LOG_ERROR, "In chunk FLI_COPY : source data (%d bytes) " \

                       "has incorrect size, skipping chunk\n", chunk_size - 6);

                bytestream2_skip(&g2, chunk_size - 6);

            } else {

                for (y_ptr = 0; check_pixel_ptr(y_ptr, s->avctx->width, pixel_limit, direction) == 0;

                     y_ptr += s->frame->linesize[0]) {

                    bytestream2_get_buffer(&g2, &pixels[y_ptr],

                                           s->avctx->width);

                    if (s->avctx->width & 3)

                        bytestream2_skip(&g2, 4 - (s->avctx->width & 3));

                }

            }

            break;

        case FLI_MINI:

            /* some sort of a thumbnail? disregard this chunk... */

            break;

        default:

            av_log(avctx, AV_LOG_ERROR, "Unrecognized chunk type: %d\n", chunk_type);

            break;

        }

        if (stream_ptr_after_chunk - bytestream2_tell(&g2) >= 0) {

            bytestream2_skip(&g2, stream_ptr_after_chunk - bytestream2_tell(&g2));

        } else {

            av_log(avctx, AV_LOG_ERROR, "Chunk overread\n");

            break;

        }

        frame_size -= chunk_size;

        num_chunks--;

    }

    /* by the end of the chunk, the stream ptr should equal the frame

     * size (minus 1 or 2, possibly); if it doesn't, issue a warning */

    if (bytestream2_get_bytes_left(&g2) > 2)

        av_log(avctx, AV_LOG_ERROR, "Processed FLI chunk where chunk size = %d " \

               "and final chunk ptr = %d\n", buf_size,

               buf_size - bytestream2_get_bytes_left(&g2));

    /* make the palette available on the way out */

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

    if (s->new_palette) {

#if FF_API_PALETTE_HAS_CHANGED

FF_DISABLE_DEPRECATION_WARNINGS

        s->frame->palette_has_changed = 1;

FF_ENABLE_DEPRECATION_WARNINGS

#endif

        s->new_palette = 0;

    }

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

        return ret;

    *got_frame = 1;

    return buf_size;

}

static int flic_decode_frame_15_16BPP(AVCodecContext *avctx,

                                      AVFrame *rframe, int *got_frame,

                                      const uint8_t *buf, int buf_size)

{

    /* Note, the only difference between the 15Bpp and 16Bpp */

    /* Format is the pixel format, the packets are processed the same. */

    FlicDecodeContext *s = avctx->priv_data;

    GetByteContext g2;

    ptrdiff_t pixel_ptr;

    unsigned char palette_idx1;

    unsigned int frame_size;

    int num_chunks;

    unsigned int chunk_size;

    int chunk_type;

    int i, j, ret, direction;

    int lines;

    int compressed_lines;

    int line_packets;

    ptrdiff_t y_ptr;

    int byte_run;

    int pixel_skip;

    int pixel_countdown;

    unsigned char *pixels;

    int pixel;

    ptrdiff_t pixel_limit;

    bytestream2_init(&g2, buf, buf_size);

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

        return ret;

    direction = s->frame->linesize[0] > 0;

    pixels = s->frame->data[0];

    pixel_limit = s->avctx->height * s->frame->linesize[0];

    frame_size = bytestream2_get_le32(&g2);

    bytestream2_skip(&g2, 2);  /* skip the magic number */

    num_chunks = bytestream2_get_le16(&g2);

    bytestream2_skip(&g2, 8);  /* skip padding */

    if (frame_size > buf_size)

        frame_size = buf_size;

    if (frame_size < 16)

        return AVERROR_INVALIDDATA;

    frame_size -= 16;

    /* iterate through the chunks */

    while ((frame_size > 0) && (num_chunks > 0) &&

            bytestream2_get_bytes_left(&g2) >= 4) {

        int stream_ptr_after_chunk;

        chunk_size = bytestream2_get_le32(&g2);

        if (chunk_size > frame_size) {

            av_log(avctx, AV_LOG_WARNING,

                   "Invalid chunk_size = %u > frame_size = %u\n", chunk_size, frame_size);

            chunk_size = frame_size;

        }

        stream_ptr_after_chunk = bytestream2_tell(&g2) - 4 + chunk_size;

        chunk_type = bytestream2_get_le16(&g2);

        switch (chunk_type) {

        case FLI_256_COLOR:

        case FLI_COLOR:

            /* For some reason, it seems that non-palettized flics do

             * include one of these chunks in their first frame.

             * Why I do not know, it seems rather extraneous. */

            ff_dlog(avctx,

                    "Unexpected Palette chunk %d in non-palettized FLC\n",

                    chunk_type);

            bytestream2_skip(&g2, chunk_size - 6);

            break;

        case FLI_DELTA:

        case FLI_DTA_LC:

            y_ptr = 0;

            compressed_lines = bytestream2_get_le16(&g2);

            while (compressed_lines > 0) {

                if (bytestream2_tell(&g2) + 2 > stream_ptr_after_chunk)

                    break;

                CHECK_Y_PTR()

                line_packets = sign_extend(bytestream2_get_le16(&g2), 16);

                if (line_packets < 0) {

                    line_packets = -line_packets;

                    if (line_packets > s->avctx->height)

                        return AVERROR_INVALIDDATA;

                    y_ptr += line_packets * s->frame->linesize[0];

                } else {

                    compressed_lines--;

                    pixel_ptr = y_ptr;

                    CHECK_PIXEL_PTR(0);

                    pixel_countdown = s->avctx->width;

                    for (i = 0; i < line_packets; i++) {

                        /* account for the skip bytes */

                        if (bytestream2_tell(&g2) + 2 > stream_ptr_after_chunk)

                            break;

                        pixel_skip = bytestream2_get_byte(&g2);

                        pixel_ptr += (pixel_skip*2); /* Pixel is 2 bytes wide */

                        pixel_countdown -= pixel_skip;

                        byte_run = sign_extend(bytestream2_get_byte(&g2), 8);

                        if (byte_run < 0) {

                            byte_run = -byte_run;

                            pixel    = bytestream2_get_le16(&g2);

                            CHECK_PIXEL_PTR(2 * byte_run);

                            for (j = 0; j < byte_run; j++, pixel_countdown -= 2) {

                                *((signed short*)(&pixels[pixel_ptr])) = pixel;

                                pixel_ptr += 2;

                            }

                        } else {

                            if (bytestream2_tell(&g2) + 2*byte_run > stream_ptr_after_chunk)

                                break;

                            CHECK_PIXEL_PTR(2 * byte_run);

                            for (j = 0; j < byte_run; j++, pixel_countdown--) {

                                *((signed short*)(&pixels[pixel_ptr])) = bytestream2_get_le16(&g2);

                                pixel_ptr += 2;

                            }

                        }

                    }

                    y_ptr += s->frame->linesize[0];

                }

            }

            break;

        case FLI_LC:

            av_log(avctx, AV_LOG_ERROR, "Unexpected FLI_LC chunk in non-palettized FLC\n");

            bytestream2_skip(&g2, chunk_size - 6);

            break;

        case FLI_BLACK:

            /* set the whole frame to 0x0000 which is black in both 15Bpp and 16Bpp modes. */

            for (int y = 0; y < s->avctx->height; y++)

                memset(pixels + y * s->frame->linesize[0], 0, s->avctx->width * 2);

            break;

        case FLI_BRUN:

            y_ptr = 0;

            for (lines = 0; lines < s->avctx->height; lines++) {

                pixel_ptr = y_ptr;

                /* disregard the line packets; instead, iterate through all

                 * pixels on a row */

                bytestream2_skip(&g2, 1);

                pixel_countdown = (s->avctx->width * 2);

                while (pixel_countdown > 0) {

                    if (bytestream2_tell(&g2) + 1 > stream_ptr_after_chunk)

                        break;

                    byte_run = sign_extend(bytestream2_get_byte(&g2), 8);

                    if (byte_run > 0) {

                        palette_idx1 = bytestream2_get_byte(&g2);

                        CHECK_PIXEL_PTR(byte_run);

                        for (j = 0; j < byte_run; j++) {

                            pixels[pixel_ptr++] = palette_idx1;

                            pixel_countdown--;

                            if (pixel_countdown < 0)

                                av_log(avctx, AV_LOG_ERROR, "pixel_countdown < 0 (%d) (linea%d)\n",

                                       pixel_countdown, lines);

                        }

                    } else {  /* copy bytes if byte_run < 0 */

                        byte_run = -byte_run;

                        if (bytestream2_tell(&g2) + byte_run > stream_ptr_after_chunk)

                            break;

                        CHECK_PIXEL_PTR(byte_run);

                        for (j = 0; j < byte_run; j++) {

                            palette_idx1 = bytestream2_get_byte(&g2);

                            pixels[pixel_ptr++] = palette_idx1;

                            pixel_countdown--;

                            if (pixel_countdown < 0)

                                av_log(avctx, AV_LOG_ERROR, "pixel_countdown < 0 (%d) at line %d\n",

                                       pixel_countdown, lines);

                        }

                    }

                }

                /* Now FLX is strange, in that it is "byte" as opposed to "pixel" run length compressed.

                 * This does not give us any good opportunity to perform word endian conversion

                 * during decompression. So if it is required (i.e., this is not a LE target, we do

                 * a second pass over the line here, swapping the bytes.

                 */

#if HAVE_BIGENDIAN

                pixel_ptr = y_ptr;

                pixel_countdown = s->avctx->width;

                while (pixel_countdown > 0) {

                    *((signed short*)(&pixels[pixel_ptr])) = AV_RL16(&buf[pixel_ptr]);

                    pixel_ptr += 2;

                }

#endif

                y_ptr += s->frame->linesize[0];

            }

            break;

        case FLI_DTA_BRUN:

            y_ptr = 0;

            for (lines = 0; lines < s->avctx->height; lines++) {

                pixel_ptr = y_ptr;

                /* disregard the line packets; instead, iterate through all

                 * pixels on a row */

                bytestream2_skip(&g2, 1);

                pixel_countdown = s->avctx->width; /* Width is in pixels, not bytes */

                while (pixel_countdown > 0) {

                    if (bytestream2_tell(&g2) + 1 > stream_ptr_after_chunk)

                        break;

                    byte_run = sign_extend(bytestream2_get_byte(&g2), 8);

                    if (byte_run > 0) {

                        pixel    = bytestream2_get_le16(&g2);

                        CHECK_PIXEL_PTR(2 * byte_run);

                        for (j = 0; j < byte_run; j++) {

                            *((signed short*)(&pixels[pixel_ptr])) = pixel;

                            pixel_ptr += 2;

                            pixel_countdown--;

                            if (pixel_countdown < 0)

                                av_log(avctx, AV_LOG_ERROR, "pixel_countdown < 0 (%d)\n",

                                       pixel_countdown);

                        }

                    } else {  /* copy pixels if byte_run < 0 */

                        byte_run = -byte_run;

                        if (bytestream2_tell(&g2) + 2 * byte_run > stream_ptr_after_chunk)

                            break;

                        CHECK_PIXEL_PTR(2 * byte_run);

                        for (j = 0; j < byte_run; j++) {

                            *((signed short*)(&pixels[pixel_ptr])) = bytestream2_get_le16(&g2);

                            pixel_ptr  += 2;

                            pixel_countdown--;

                            if (pixel_countdown < 0)

                                av_log(avctx, AV_LOG_ERROR, "pixel_countdown < 0 (%d)\n",

                                       pixel_countdown);

                        }

                    }

                }

                y_ptr += s->frame->linesize[0];

            }

            break;

        case FLI_COPY:

        case FLI_DTA_COPY:

            /* copy the chunk (uncompressed frame) */

            if (chunk_size - 6 > (unsigned int)(FFALIGN(s->avctx->width, 2) * s->avctx->height)*2) {

                av_log(avctx, AV_LOG_ERROR, "In chunk FLI_COPY : source data (%d bytes) " \

                       "bigger than image, skipping chunk\n", chunk_size - 6);

                bytestream2_skip(&g2, chunk_size - 6);

            } else {

                if (bytestream2_get_bytes_left(&g2) < 2 * s->avctx->width * s->avctx->height )

                    return AVERROR_INVALIDDATA;

                for (y_ptr = 0; check_pixel_ptr(y_ptr, 2*s->avctx->width, pixel_limit, direction) == 0;

                     y_ptr += s->frame->linesize[0]) {

                    pixel_countdown = s->avctx->width;

                    pixel_ptr = 0;

                    while (pixel_countdown > 0) {

                      *((signed short*)(&pixels[y_ptr + pixel_ptr])) = bytestream2_get_le16(&g2);

                      pixel_ptr += 2;

                      pixel_countdown--;

                    }

                    if (s->avctx->width & 1)

                        bytestream2_skip(&g2, 2);

                }

            }

            break;

        case FLI_MINI:

            /* some sort of a thumbnail? disregard this chunk... */

            bytestream2_skip(&g2, chunk_size - 6);

            break;

        default:

            av_log(avctx, AV_LOG_ERROR, "Unrecognized chunk type: %d\n", chunk_type);

            break;

        }

        if (stream_ptr_after_chunk - bytestream2_tell(&g2) >= 0) {

            bytestream2_skip(&g2, stream_ptr_after_chunk - bytestream2_tell(&g2));

        } else {

            av_log(avctx, AV_LOG_ERROR, "Chunk overread\n");

            break;

        }

        frame_size -= chunk_size;

        num_chunks--;

    }

    /* by the end of the chunk, the stream ptr should equal the frame

     * size (minus 1, possibly); if it doesn't, issue a warning */

    if ((bytestream2_get_bytes_left(&g2) != 0) && (bytestream2_get_bytes_left(&g2) != 1))

        av_log(avctx, AV_LOG_ERROR, "Processed FLI chunk where chunk size = %d " \

               "and final chunk ptr = %d\n", buf_size, bytestream2_tell(&g2));

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

        return ret;

    *got_frame = 1;

    return buf_size;

}

static int flic_decode_frame_24BPP(AVCodecContext *avctx,

                                   AVFrame *rframe, int *got_frame,

                                   const uint8_t *buf, int buf_size)

{

    FlicDecodeContext *s = avctx->priv_data;

    GetByteContext g2;

    ptrdiff_t pixel_ptr;

    unsigned char palette_idx1;

    unsigned int frame_size;

    int num_chunks;

    unsigned int chunk_size;

    int chunk_type;

    int i, j, ret, direction;

    int lines;

    int compressed_lines;

    int line_packets;

    ptrdiff_t y_ptr;

    int byte_run;

    int pixel_skip;

    int pixel_countdown;

    unsigned char *pixels;

    int pixel;