hvirtual/quicktime/ffmpeg/libavcodec/idcinvideo.c File Reference

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

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Data Structures
struct	hnode_t
struct	IdcinContext
Defines
#define	HUFFMAN_TABLE_SIZE   64 * 1024
#define	HUF_TOKENS   256
#define	PALETTE_COUNT   256
Functions
static int	huff_smallest_node (hnode_t *hnodes, int num_hnodes)
static void	huff_build_tree (IdcinContext *s, int prev)
static int	idcin_decode_init (AVCodecContext *avctx)
static void	idcin_decode_vlcs (IdcinContext *s)
static int	idcin_decode_frame (AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size)
static int	idcin_decode_end (AVCodecContext *avctx)
Variables
AVCodec	idcin_decoder

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Detailed Description

Id Quake II Cin Video Decoder by Dr. Tim Ferguson For more information about the Id CIN format, visit: http://www.csse.monash.edu.au/~timf/

This video decoder outputs PAL8 colorspace data. Interacting with this decoder is a little involved. During initialization, the demuxer must transmit the 65536-byte Huffman table(s) to the decoder via extradata. Then, whenever a palette change is encountered while demuxing the file, the demuxer must use the same extradata space to transmit an AVPaletteControl structure.

Id CIN video is purely Huffman-coded, intraframe-only codec. It achieves a little more compression by exploiting the fact that adjacent pixels tend to be similar.

Note that this decoder could use ffmpeg's optimized VLC facilities rather than naive, tree-based Huffman decoding. However, there are 256 Huffman tables. Plus, the VLC bit coding order is right -> left instead or left -> right, so all of the bits would have to be reversed. Further, the original Quake II implementation likely used a similar naive decoding algorithm and it worked fine on much lower spec machines.

Definition in file idcinvideo.c.

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Define Documentation

#define HUF_TOKENS   256

Definition at line 56 of file idcinvideo.c.

Referenced by huff_build_tree(), idcin_decode_init(), and idcin_decode_vlcs().

#define HUFFMAN_TABLE_SIZE   64 * 1024

Definition at line 55 of file idcinvideo.c.

Referenced by idcin_decode_init().

#define PALETTE_COUNT   256

Definition at line 57 of file idcinvideo.c.

Referenced by idcin_decode_frame(), ipvideo_decode_opcodes(), vmd_decode(), vmdvideo_decode_frame(), vmdvideo_decode_init(), vqa_decode_frame(), xan_wc3_build_palette(), and xan_wc3_decode_frame().

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Function Documentation

static void huff_build_tree	(	IdcinContext *	s,
		int	prev
	)			[static]

Definition at line 118 of file idcinvideo.c.

References hnode_t::children, hnode_t::count, HUF_TOKENS, IdcinContext::huff_nodes, huff_smallest_node(), and IdcinContext::num_huff_nodes.

Referenced by idcin_decode_init().

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static int huff_smallest_node	(	hnode_t *	hnodes,
		int	num_hnodes
	)			[static]

Definition at line 86 of file idcinvideo.c.

References hnode_t::count, and hnode_t::used.

Referenced by huff_build_tree().

static int idcin_decode_end

(

AVCodecContext *

avctx

)

[static]

Definition at line 249 of file idcinvideo.c.

References IdcinContext::frame, AVCodecContext::priv_data, AVCodecContext::release_buffer, and s.

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

Definition at line 214 of file idcinvideo.c.

References av_log(), AV_LOG_ERROR, IdcinContext::buf, IdcinContext::frame, AVCodecContext::get_buffer, idcin_decode_vlcs(), memcpy, AVCodecContext::palctrl, PALETTE_COUNT, AVCodecContext::priv_data, AVCodecContext::release_buffer, s, and IdcinContext::size.

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static int idcin_decode_init

(

AVCodecContext *

avctx

)

[static]

Definition at line 148 of file idcinvideo.c.

References av_log(), AV_LOG_ERROR, IdcinContext::avctx, hnode_t::count, IdcinContext::dsp, dsputil_init(), AVCodecContext::extradata, AVCodecContext::extradata_size, IdcinContext::frame, AVCodecContext::has_b_frames, HUF_TOKENS, huff_build_tree(), IdcinContext::huff_nodes, HUFFMAN_TABLE_SIZE, NULL, AVCodecContext::pix_fmt, PIX_FMT_PAL8, AVCodecContext::priv_data, and s.

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static void idcin_decode_vlcs

(

IdcinContext *

s

)

[static]

Definition at line 178 of file idcinvideo.c.

References av_log(), AV_LOG_ERROR, IdcinContext::avctx, IdcinContext::buf, hnode_t::children, IdcinContext::frame, AVCodecContext::height, HUF_TOKENS, IdcinContext::huff_nodes, IdcinContext::num_huff_nodes, IdcinContext::size, and AVCodecContext::width.

Referenced by idcin_decode_frame().

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Variable Documentation

AVCodec idcin_decoder

Initial value:

 {
    "idcinvideo",
    CODEC_TYPE_VIDEO,
    CODEC_ID_IDCIN,
    sizeof(IdcinContext),
    idcin_decode_init,
    NULL,
    idcin_decode_end,
    idcin_decode_frame,
    CODEC_CAP_DR1,
}

Definition at line 259 of file idcinvideo.c.

Referenced by avcodec_register_all().