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ffmpeg / libavcodec / oggtheora.c @ d2d230a7

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/**
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    Copyright (C) 2005  Måns Rullgård
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    Permission is hereby granted, free of charge, to any person
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    obtaining a copy of this software and associated documentation
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    files (the "Software"), to deal in the Software without
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    restriction, including without limitation the rights to use, copy,
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    modify, merge, publish, distribute, sublicense, and/or sell copies
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    of the Software, and to permit persons to whom the Software is
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    furnished to do so, subject to the following conditions:
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    The above copyright notice and this permission notice shall be
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    included in all copies or substantial portions of the Software.
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    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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    DEALINGS IN THE SOFTWARE.
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**/
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#include <stdlib.h>
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#include <theora/theora.h>
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#include "avcodec.h"
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typedef struct TheoraContext {
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    theora_info info;
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    theora_state state;
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    theora_comment comment;
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    ogg_packet op;
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} TheoraContext;
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static int
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Theora_decode_frame(AVCodecContext *ctx, void *outdata, int *outdata_size,
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                    uint8_t *buf, int buf_size)
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{
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    TheoraContext *thc = ctx->priv_data;
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    AVFrame *frame = outdata;
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    yuv_buffer yuv;
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    thc->op.packet = buf;
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    thc->op.bytes = buf_size;
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    if(theora_decode_packetin(&thc->state, &thc->op))
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        return -1;
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    theora_decode_YUVout(&thc->state, &yuv);
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    frame->data[0] = yuv.y;
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    frame->data[1] = yuv.u;
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    frame->data[2] = yuv.v;
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    frame->linesize[0] = yuv.y_stride;
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    frame->linesize[1] = yuv.uv_stride;
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    frame->linesize[2] = yuv.uv_stride;
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    *outdata_size = sizeof(*frame);
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    return buf_size;
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}
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static int
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Theora_decode_end(AVCodecContext *ctx)
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{
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    TheoraContext *thc = ctx->priv_data;
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    theora_info_clear(&thc->info);
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    theora_comment_clear(&thc->comment);
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    return 0;
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}
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static int
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Theora_decode_init(AVCodecContext *ctx)
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{
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    TheoraContext *thc = ctx->priv_data;
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    int size, hs, i;
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    ogg_packet op;
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    uint8_t *cdp;
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    if(ctx->extradata_size < 6)
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        return -1;
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    theora_info_init(&thc->info);
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    memset(&op, 0, sizeof(op));
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    cdp = ctx->extradata;
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    size = ctx->extradata_size;
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    for(i = 0; i < 3; i++){
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        hs = *cdp++ << 8;
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        hs += *cdp++;
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        size -= 2;
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        if(hs > size){
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            av_log(ctx, AV_LOG_ERROR, "extradata too small: %i > %i\n",
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                   hs, size);
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            return -1;
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        }
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        op.packet = cdp;
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        op.bytes = hs;
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        op.b_o_s = !i;
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        if(theora_decode_header(&thc->info, &thc->comment, &op))
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            return -1;
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        op.packetno++;
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        cdp += hs;
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        size -= hs;
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    }
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    theora_decode_init(&thc->state, &thc->info);
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    ctx->width = thc->info.width;
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    ctx->height = thc->info.height;
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    ctx->time_base.num = thc->info.fps_denominator;
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    ctx->time_base.den = thc->info.fps_numerator;
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    ctx->pix_fmt = PIX_FMT_YUV420P; /* FIXME: others are possible */
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    return 0;
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}
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AVCodec oggtheora_decoder = {
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    "theora",
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    CODEC_TYPE_VIDEO,
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    CODEC_ID_THEORA,
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    sizeof(TheoraContext),
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    Theora_decode_init,
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    NULL,
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    Theora_decode_end,
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    Theora_decode_frame,
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    0,
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    NULL
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};