aasc.c File Reference

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "avcodec.h"
#include "dsputil.h"

Go to the source code of this file.

Data Structures
struct	AascContext
Defines
#define	FETCH_NEXT_STREAM_BYTE()
Functions
static av_cold int	aasc_decode_init (AVCodecContext *avctx)
static int	aasc_decode_frame (AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
static av_cold int	aasc_decode_end (AVCodecContext *avctx)
Variables
AVCodec	aasc_decoder

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Detailed Description

Autodesk RLE Video Decoder by Konstantin Shishkov

Definition in file aasc.c.

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Define Documentation

 

#define FETCH_NEXT_STREAM_BYTE

(

)

Value:

if (stream_ptr >= buf_size) \
    { \
      av_log(s->avctx, AV_LOG_ERROR, " AASC: stream ptr just went out of bounds (fetch)\n"); \
      break; \
    } \
    stream_byte = buf[stream_ptr++];

Definition at line 39 of file aasc.c.

Referenced by aasc_decode_frame(), msrle_decode_pal4(), and msrle_decode_pal8().

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Function Documentation

static av_cold int aasc_decode_end

(

AVCodecContext *

avctx

)

[static]

Definition at line 153 of file aasc.c.

References AascContext::frame, AVCodecContext::priv_data, and AVCodecContext::release_buffer.

{
    AascContext *s = avctx->priv_data;

    /* release the last frame */
    if (s->frame.data[0])
        avctx->release_buffer(avctx, &s->frame);

    return 0;
}

static int aasc_decode_frame	(	AVCodecContext *	avctx,
		void *	data,
		int *	data_size,
		const uint8_t *	buf,
		int	buf_size
	)			[static]

Definition at line 59 of file aasc.c.

References av_log(), AV_LOG_ERROR, AascContext::avctx, FETCH_NEXT_STREAM_BYTE, FF_BUFFER_HINTS_PRESERVE, FF_BUFFER_HINTS_REUSABLE, FF_BUFFER_HINTS_VALID, AascContext::frame, AVCodecContext::height, AVCodecContext::priv_data, AVCodecContext::reget_buffer, and AVCodecContext::width.

{
    AascContext *s = avctx->priv_data;
    int stream_ptr = 4;
    unsigned char rle_code;
    unsigned char stream_byte;
    int pixel_ptr = 0;
    int row_dec, row_ptr;
    int frame_size;
    int i;

    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)) {
        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
        return -1;
    }

    row_dec = s->frame.linesize[0];
    row_ptr = (s->avctx->height - 1) * row_dec;
    frame_size = row_dec * s->avctx->height;

    while (row_ptr >= 0) {
        FETCH_NEXT_STREAM_BYTE();
        rle_code = stream_byte;
        if (rle_code == 0) {
            /* fetch the next byte to see how to handle escape code */
            FETCH_NEXT_STREAM_BYTE();
            if (stream_byte == 0) {
                /* line is done, goto the next one */
                row_ptr -= row_dec;
                pixel_ptr = 0;
            } else if (stream_byte == 1) {
                /* decode is done */
                break;
            } else if (stream_byte == 2) {
                /* reposition frame decode coordinates */
                FETCH_NEXT_STREAM_BYTE();
                pixel_ptr += stream_byte;
                FETCH_NEXT_STREAM_BYTE();
                row_ptr -= stream_byte * row_dec;
            } else {
                /* copy pixels from encoded stream */
                if ((pixel_ptr + stream_byte > avctx->width * 3) ||
                    (row_ptr < 0)) {
                    av_log(s->avctx, AV_LOG_ERROR, " AASC: frame ptr just went out of bounds (copy1)\n");
                    break;
                }

                rle_code = stream_byte;
                if (stream_ptr + rle_code > buf_size) {
                    av_log(s->avctx, AV_LOG_ERROR, " AASC: stream ptr just went out of bounds (copy2)\n");
                    break;
                }

                for (i = 0; i < rle_code; i++) {
                    FETCH_NEXT_STREAM_BYTE();
                    s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
                    pixel_ptr++;
                }
                if (rle_code & 1)
                    stream_ptr++;
            }
        } else {
            /* decode a run of data */
            if ((pixel_ptr + rle_code > avctx->width * 3) ||
                (row_ptr < 0)) {
                av_log(s->avctx, AV_LOG_ERROR, " AASC: frame ptr just went out of bounds (run1)\n");
                break;
            }

            FETCH_NEXT_STREAM_BYTE();

            while(rle_code--) {
                s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
                pixel_ptr++;
            }
        }
    }

    /* one last sanity check on the way out */
    if (stream_ptr < buf_size)
        av_log(s->avctx, AV_LOG_ERROR, " AASC: ended frame decode with bytes left over (%d < %d)\n",
            stream_ptr, buf_size);

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

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

static av_cold int aasc_decode_init

(

AVCodecContext *

avctx

)

[static]

Definition at line 47 of file aasc.c.

References AascContext::avctx, AascContext::frame, NULL, AVCodecContext::pix_fmt, PIX_FMT_BGR24, and AVCodecContext::priv_data.

{
    AascContext *s = avctx->priv_data;

    s->avctx = avctx;

    avctx->pix_fmt = PIX_FMT_BGR24;
    s->frame.data[0] = NULL;

    return 0;
}

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Variable Documentation

AVCodec aasc_decoder

Initial value:

 {
    "aasc",
    CODEC_TYPE_VIDEO,
    CODEC_ID_AASC,
    sizeof(AascContext),
    aasc_decode_init,
    NULL,
    aasc_decode_end,
    aasc_decode_frame,
    CODEC_CAP_DR1,
    .long_name = NULL_IF_CONFIG_SMALL("Autodesk RLE"),
}

Definition at line 164 of file aasc.c.

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