PeerStreamer

/*

 * 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 and maybe one day RGB24

 * colorspace data, depending on the FLC. 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 <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "libavutil/intreadwrite.h"

#include "avcodec.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)

#define CHECK_PIXEL_PTR(n) \

    if (pixel_ptr + n > pixel_limit) { \

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

        pixel_ptr + n, pixel_limit); \

        return -1; \

    } \

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;

    unsigned char *fli_header = (unsigned char *)avctx->extradata;

    int depth;

    s->avctx = avctx;

    s->fli_type = AV_RL16(&fli_header[4]); /* Might be overridden if a Magic Carpet FLC */

    depth = 0;

    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 (s->avctx->extradata_size != 128) {

        av_log(avctx, AV_LOG_ERROR, "Expected extradata of 12 or 128 bytes\n");

        return -1;

    } else {

        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 8  : avctx->pix_fmt = PIX_FMT_PAL8; break;

        case 15 : avctx->pix_fmt = PIX_FMT_RGB555; break;

        case 16 : avctx->pix_fmt = PIX_FMT_RGB565; break;

        case 24 : avctx->pix_fmt = PIX_FMT_BGR24; /* Supposedly BGR, but havent any files to test with */

                  av_log(avctx, AV_LOG_ERROR, "24Bpp FLC/FLX is unsupported due to no test files.\n");

                  return -1;

                  break;

        default :

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

                  return -1;

    }

    s->frame.data[0] = NULL;

    s->new_palette = 0;

    return 0;

}

static int flic_decode_frame_8BPP(AVCodecContext *avctx,

                                  void *data, int *data_size,

                                  const uint8_t *buf, int buf_size)

{

    FlicDecodeContext *s = avctx->priv_data;

    int stream_ptr = 0;

    int stream_ptr_after_color_chunk;

    int 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;

    int color_packets;

    int color_changes;

    int color_shift;

    unsigned char r, g, b;

    int lines;

    int compressed_lines;

    int starting_line;

    signed short line_packets;

    int y_ptr;

    int byte_run;

    int pixel_skip;

    int pixel_countdown;

    unsigned char *pixels;

    unsigned int pixel_limit;

    s->frame.reference = 1;

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

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

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

        return -1;

    }

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

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

    frame_size = AV_RL32(&buf[stream_ptr]);

    stream_ptr += 6;  /* skip the magic number */

    num_chunks = AV_RL16(&buf[stream_ptr]);

    stream_ptr += 10;  /* skip padding */

    frame_size -= 16;

    /* iterate through the chunks */

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

        chunk_size = AV_RL32(&buf[stream_ptr]);

        stream_ptr += 4;

        chunk_type = AV_RL16(&buf[stream_ptr]);

        stream_ptr += 2;

        switch (chunk_type) {

        case FLI_256_COLOR:

        case FLI_COLOR:

            stream_ptr_after_color_chunk = stream_ptr + chunk_size - 6;

            /* 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 = AV_RL16(&buf[stream_ptr]);

            stream_ptr += 2;

            palette_ptr = 0;

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

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

                palette_ptr += buf[stream_ptr++];

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

                color_changes = buf[stream_ptr++];

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

                if (color_changes == 0)

                    color_changes = 256;

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

                    unsigned int entry;

                    /* wrap around, for good measure */

                    if ((unsigned)palette_ptr >= 256)

                        palette_ptr = 0;

                    r = buf[stream_ptr++] << color_shift;

                    g = buf[stream_ptr++] << color_shift;

                    b = buf[stream_ptr++] << color_shift;

                    entry = (r << 16) | (g << 8) | b;

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

                        s->new_palette = 1;

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

                }

            }

            /* color chunks sometimes have weird 16-bit alignment issues;

             * therefore, take the hardline approach and set the stream_ptr

             * to the value calculated w.r.t. the size specified by the color

             * chunk header */

            stream_ptr = stream_ptr_after_color_chunk;

            break;

        case FLI_DELTA:

            y_ptr = 0;

            compressed_lines = AV_RL16(&buf[stream_ptr]);

            stream_ptr += 2;

            while (compressed_lines > 0) {

                line_packets = AV_RL16(&buf[stream_ptr]);

                stream_ptr += 2;

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

                    // line skip opcode

                    line_packets = -line_packets;

                    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++) {

                        /* account for the skip bytes */

                        pixel_skip = buf[stream_ptr++];

                        pixel_ptr += pixel_skip;

                        pixel_countdown -= pixel_skip;

                        byte_run = (signed char)(buf[stream_ptr++]);

                        if (byte_run < 0) {

                            byte_run = -byte_run;

                            palette_idx1 = buf[stream_ptr++];

                            palette_idx2 = buf[stream_ptr++];

                            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);

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

                                palette_idx1 = buf[stream_ptr++];

                                pixels[pixel_ptr++] = palette_idx1;

                            }

                        }

                    }

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

                }

            }

            break;

        case FLI_LC:

            /* line compressed */

            starting_line = AV_RL16(&buf[stream_ptr]);

            stream_ptr += 2;

            y_ptr = 0;

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

            compressed_lines = AV_RL16(&buf[stream_ptr]);

            stream_ptr += 2;

            while (compressed_lines > 0) {

                pixel_ptr = y_ptr;

                CHECK_PIXEL_PTR(0);

                pixel_countdown = s->avctx->width;

                line_packets = buf[stream_ptr++];

                if (line_packets > 0) {

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

                        /* account for the skip bytes */

                        pixel_skip = buf[stream_ptr++];

                        pixel_ptr += pixel_skip;

                        pixel_countdown -= pixel_skip;

                        byte_run = (signed char)(buf[stream_ptr++]);

                        if (byte_run > 0) {

                            CHECK_PIXEL_PTR(byte_run);

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

                                palette_idx1 = buf[stream_ptr++];

                                pixels[pixel_ptr++] = palette_idx1;

                            }

                        } else if (byte_run < 0) {

                            byte_run = -byte_run;

                            palette_idx1 = buf[stream_ptr++];

                            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) */

            memset(pixels, 0,

                s->frame.linesize[0] * s->avctx->height);

            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 */

                stream_ptr++;

                pixel_countdown = s->avctx->width;

                while (pixel_countdown > 0) {

                    byte_run = (signed char)(buf[stream_ptr++]);

                    if (byte_run > 0) {

                        palette_idx1 = buf[stream_ptr++];

                        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);

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

                            palette_idx1 = buf[stream_ptr++];

                            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);

                        }

                    }

                }

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

            }

            break;

        case FLI_COPY:

            /* copy the chunk (uncompressed frame) */

            if (chunk_size - 6 > s->avctx->width * s->avctx->height) {

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

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

                stream_ptr += chunk_size - 6;

            } else {

                for (y_ptr = 0; y_ptr < s->frame.linesize[0] * s->avctx->height;

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

                    memcpy(&pixels[y_ptr], &buf[stream_ptr],

                        s->avctx->width);

                    stream_ptr += s->avctx->width;

                }

            }

            break;

        case FLI_MINI:

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

            stream_ptr += chunk_size - 6;

            break;

        default:

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

            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 ((stream_ptr != buf_size) && (stream_ptr != buf_size - 1))

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

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

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

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

    if (s->new_palette) {

        s->frame.palette_has_changed = 1;

        s->new_palette = 0;

    }

    *data_size=sizeof(AVFrame);

    *(AVFrame*)data = s->frame;

    return buf_size;

}

static int flic_decode_frame_15_16BPP(AVCodecContext *avctx,

                                      void *data, int *data_size,

                                      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;

    int stream_ptr = 0;

    int pixel_ptr;

    unsigned char palette_idx1;

    unsigned int frame_size;

    int num_chunks;

    unsigned int chunk_size;

    int chunk_type;

    int i, j;

    int lines;

    int compressed_lines;

    signed short line_packets;

    int y_ptr;

    int byte_run;

    int pixel_skip;

    int pixel_countdown;

    unsigned char *pixels;

    int pixel;

    unsigned int pixel_limit;

    s->frame.reference = 1;

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

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

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

        return -1;

    }

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

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

    frame_size = AV_RL32(&buf[stream_ptr]);

    stream_ptr += 6;  /* skip the magic number */

    num_chunks = AV_RL16(&buf[stream_ptr]);

    stream_ptr += 10;  /* skip padding */

    frame_size -= 16;

    /* iterate through the chunks */

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

        chunk_size = AV_RL32(&buf[stream_ptr]);

        stream_ptr += 4;

        chunk_type = AV_RL16(&buf[stream_ptr]);

        stream_ptr += 2;

        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. */

/*            av_log(avctx, AV_LOG_ERROR, "Unexpected Palette chunk %d in non-paletised FLC\n",chunk_type);*/

            stream_ptr = stream_ptr + chunk_size - 6;

            break;

        case FLI_DELTA:

        case FLI_DTA_LC:

            y_ptr = 0;

            compressed_lines = AV_RL16(&buf[stream_ptr]);

            stream_ptr += 2;

            while (compressed_lines > 0) {

                line_packets = AV_RL16(&buf[stream_ptr]);

                stream_ptr += 2;

                if (line_packets < 0) {

                    line_packets = -line_packets;

                    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 */

                        pixel_skip = buf[stream_ptr++];

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

                        pixel_countdown -= pixel_skip;

                        byte_run = (signed char)(buf[stream_ptr++]);

                        if (byte_run < 0) {

                            byte_run = -byte_run;

                            pixel    = AV_RL16(&buf[stream_ptr]);

                            stream_ptr += 2;

                            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 {

                            CHECK_PIXEL_PTR(2 * byte_run);

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

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

                                stream_ptr += 2;

                                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-paletised FLC\n");

            stream_ptr = stream_ptr + chunk_size - 6;

            break;

        case FLI_BLACK:

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

            memset(pixels, 0x0000,

                   s->frame.linesize[0] * s->avctx->height);

            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 */

                stream_ptr++;

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

                while (pixel_countdown > 0) {

                    byte_run = (signed char)(buf[stream_ptr++]);

                    if (byte_run > 0) {

                        palette_idx1 = buf[stream_ptr++];

                        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;

                        CHECK_PIXEL_PTR(byte_run);

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

                            palette_idx1 = buf[stream_ptr++];

                            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 oportunity 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 */

                stream_ptr++;

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

                while (pixel_countdown > 0) {

                    byte_run = (signed char)(buf[stream_ptr++]);

                    if (byte_run > 0) {

                        pixel    = AV_RL16(&buf[stream_ptr]);

                        stream_ptr += 2;

                        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;

                        CHECK_PIXEL_PTR(2 * byte_run);

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

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

                            stream_ptr += 2;

                            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)(s->avctx->width * 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);

                stream_ptr += chunk_size - 6;

            } else {

                for (y_ptr = 0; y_ptr < s->frame.linesize[0] * s->avctx->height;

                     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])) = AV_RL16(&buf[stream_ptr+pixel_ptr]);

                      pixel_ptr += 2;

                      pixel_countdown--;

                    }

                    stream_ptr += s->avctx->width*2;

                }

            }

            break;

        case FLI_MINI:

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

            stream_ptr += chunk_size - 6;

            break;

        default:

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

            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 ((stream_ptr != buf_size) && (stream_ptr != buf_size - 1))

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

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

    *data_size=sizeof(AVFrame);

    *(AVFrame*)data = s->frame;

    return buf_size;

}

static int flic_decode_frame_24BPP(AVCodecContext *avctx,

                                   void *data, int *data_size,

                                   const uint8_t *buf, int buf_size)

{

  av_log(avctx, AV_LOG_ERROR, "24Bpp FLC Unsupported due to lack of test files.\n");

  return -1;

}

static int flic_decode_frame(AVCodecContext *avctx,

                             void *data, int *data_size,

                             AVPacket *avpkt)

{

    const uint8_t *buf = avpkt->data;

    int buf_size = avpkt->size;

    if (avctx->pix_fmt == PIX_FMT_PAL8) {

      return flic_decode_frame_8BPP(avctx, data, data_size,

                                    buf, buf_size);

    }

    else if ((avctx->pix_fmt == PIX_FMT_RGB555) ||

             (avctx->pix_fmt == PIX_FMT_RGB565)) {

      return flic_decode_frame_15_16BPP(avctx, data, data_size,

                                        buf, buf_size);

    }

    else if (avctx->pix_fmt == PIX_FMT_BGR24) {

      return flic_decode_frame_24BPP(avctx, data, data_size,

                                     buf, buf_size);

    }

    /* Should not get  here, ever as the pix_fmt is processed */

    /* in flic_decode_init and the above if should deal with */

    /* the finite set of possibilites allowable by here. */

    /* But in case we do, just error out. */

    av_log(avctx, AV_LOG_ERROR, "Unknown FLC format, my science cannot explain how this happened.\n");

    return -1;

}

static av_cold int flic_decode_end(AVCodecContext *avctx)

{

    FlicDecodeContext *s = avctx->priv_data;

    if (s->frame.data[0])

        avctx->release_buffer(avctx, &s->frame);

    return 0;

}

AVCodec ff_flic_decoder = {

    "flic",

    AVMEDIA_TYPE_VIDEO,

    CODEC_ID_FLIC,

    sizeof(FlicDecodeContext),

    flic_decode_init,

    NULL,

    flic_decode_end,

    flic_decode_frame,

    CODEC_CAP_DR1,

    NULL,

    NULL,

    NULL,

    NULL,

    .long_name = NULL_IF_CONFIG_SMALL("Autodesk Animator Flic video"),

};