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ffmpeg / libavcodec / jvdec.c @ 2912e87a

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/*
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 * Bitmap Brothers JV video decoder
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 * Copyright (c) 2011 Peter Ross <pross@xvid.org>
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 *
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 * This file is part of Libav.
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 *
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 * Libav is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * Libav is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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 * Bitmap Brothers JV video decoder
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 * @author Peter Ross <pross@xvid.org>
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 */
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#include "avcodec.h"
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#include "dsputil.h"
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#include "get_bits.h"
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#include "libavutil/intreadwrite.h"
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typedef struct JvContext {
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    DSPContext dsp;
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    AVFrame    frame;
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    uint32_t   palette[AVPALETTE_COUNT];
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    int        palette_has_changed;
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} JvContext;
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static av_cold int decode_init(AVCodecContext *avctx)
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{
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    JvContext *s = avctx->priv_data;
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    avctx->pix_fmt = PIX_FMT_PAL8;
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    dsputil_init(&s->dsp, avctx);
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    return 0;
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}
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/**
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 * Decode 2x2 block
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 */
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static inline void decode2x2(GetBitContext *gb, uint8_t *dst, int linesize)
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{
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    int i, j, v[2];
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    switch (get_bits(gb, 2)) {
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    case 1:
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        v[0] = get_bits(gb, 8);
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        for (j = 0; j < 2; j++)
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            memset(dst + j*linesize, v[0], 2);
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        break;
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    case 2:
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        v[0] = get_bits(gb, 8);
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        v[1] = get_bits(gb, 8);
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        for (j = 0; j < 2; j++)
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            for (i = 0; i < 2; i++)
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                dst[j*linesize + i] = v[get_bits1(gb)];
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        break;
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    case 3:
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        for (j = 0; j < 2; j++)
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            for (i = 0; i < 2; i++)
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                dst[j*linesize + i] = get_bits(gb, 8);
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    }
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}
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/**
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 * Decode 4x4 block
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 */
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static inline void decode4x4(GetBitContext *gb, uint8_t *dst, int linesize)
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{
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    int i, j, v[2];
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    switch (get_bits(gb, 2)) {
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    case 1:
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        v[0] = get_bits(gb, 8);
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        for (j = 0; j < 4; j++)
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            memset(dst + j*linesize, v[0], 4);
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        break;
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    case 2:
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        v[0] = get_bits(gb, 8);
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        v[1] = get_bits(gb, 8);
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        for (j = 2; j >= 0; j -= 2) {
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            for (i = 0; i < 4; i++)
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                dst[j*linesize + i]     = v[get_bits1(gb)];
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            for (i = 0; i < 4; i++)
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                dst[(j+1)*linesize + i] = v[get_bits1(gb)];
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        }
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        break;
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    case 3:
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        for (j = 0; j < 4; j += 2)
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            for (i = 0; i < 4; i += 2)
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                decode2x2(gb, dst + j*linesize + i, linesize);
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    }
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}
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/**
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 * Decode 8x8 block
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 */
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static inline void decode8x8(GetBitContext *gb, uint8_t *dst, int linesize, DSPContext *dsp)
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{
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    int i, j, v[2];
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    switch (get_bits(gb, 2)) {
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    case 1:
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        v[0] = get_bits(gb, 8);
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        dsp->fill_block_tab[1](dst, v[0], linesize, 8);
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        break;
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    case 2:
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        v[0] = get_bits(gb, 8);
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        v[1] = get_bits(gb, 8);
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        for (j = 7; j >= 0; j--)
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            for (i = 0; i <  8; i++)
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                dst[j*linesize + i] = v[get_bits1(gb)];
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        break;
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    case 3:
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        for (j = 0; j < 8; j += 4)
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            for (i = 0; i < 8; i += 4)
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                decode4x4(gb, dst + j*linesize + i, linesize);
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    }
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}
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static int decode_frame(AVCodecContext *avctx,
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                        void *data, int *data_size,
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                        AVPacket *avpkt)
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{
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    JvContext *s           = avctx->priv_data;
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    int buf_size           = avpkt->size;
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    const uint8_t *buf     = avpkt->data;
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    const uint8_t *buf_end = buf + buf_size;
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    int video_size, video_type, i, j;
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    video_size = AV_RL32(buf);
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    video_type = buf[4];
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    buf += 5;
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    if (video_size) {
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        if (avctx->reget_buffer(avctx, &s->frame) < 0) {
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            av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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            return -1;
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        }
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        if (video_type == 0 || video_type == 1) {
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            GetBitContext gb;
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            init_get_bits(&gb, buf, FFMIN(video_size, buf_end - buf));
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            for (j = 0; j < avctx->height; j += 8)
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                for (i = 0; i < avctx->width; i += 8)
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                    decode8x8(&gb, s->frame.data[0] + j*s->frame.linesize[0] + i,
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                              s->frame.linesize[0], &s->dsp);
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            buf += video_size;
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        } else if (video_type == 2) {
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            if (buf + 1 <= buf_end) {
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                int v = *buf++;
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                for (j = 0; j < avctx->height; j++)
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                    memset(s->frame.data[0] + j*s->frame.linesize[0], v, avctx->width);
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            }
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        } else {
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            av_log(avctx, AV_LOG_WARNING, "unsupported frame type %i\n", video_type);
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            return AVERROR_INVALIDDATA;
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        }
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    }
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    if (buf < buf_end) {
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        for (i = 0; i < AVPALETTE_COUNT && buf + 3 <= buf_end; i++) {
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            s->palette[i] = AV_RB24(buf) << 2;
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            buf += 3;
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        }
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        s->palette_has_changed = 1;
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    }
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    if (video_size) {
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        s->frame.key_frame           = 1;
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        s->frame.pict_type           = FF_I_TYPE;
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        s->frame.palette_has_changed = s->palette_has_changed;
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        s->palette_has_changed       = 0;
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        memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
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        *data_size      = sizeof(AVFrame);
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        *(AVFrame*)data = s->frame;
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    }
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    return buf_size;
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}
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static av_cold int decode_close(AVCodecContext *avctx)
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{
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    JvContext *s = avctx->priv_data;
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    if(s->frame.data[0])
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        avctx->release_buffer(avctx, &s->frame);
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    return 0;
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}
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AVCodec ff_jv_decoder = {
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    .name           = "jv",
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    .long_name      = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV video"),
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    .type           = CODEC_TYPE_VIDEO,
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    .id             = CODEC_ID_JV,
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    .priv_data_size = sizeof(JvContext),
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    .init           = decode_init,
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    .close          = decode_close,
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    .decode         = decode_frame,
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    .capabilities   = CODEC_CAP_DR1,
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};