FFmpeg/libavcodec/bitstream_filter.c

/*
 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
 *
 * 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
 */

#include "avcodec.h"

AVBitStreamFilter *first_bitstream_filter= NULL;

void av_register_bitstream_filter(AVBitStreamFilter *bsf){
    bsf->next = first_bitstream_filter;
    first_bitstream_filter= bsf;
}

AVBitStreamFilterContext *av_bitstream_filter_init(const char *name){
    AVBitStreamFilter *bsf= first_bitstream_filter;

    while(bsf){
        if(!strcmp(name, bsf->name)){
            AVBitStreamFilterContext *bsfc= av_mallocz(sizeof(AVBitStreamFilterContext));
            bsfc->filter= bsf;
            bsfc->priv_data= av_mallocz(bsf->priv_data_size);
            return bsfc;
        }
        bsf= bsf->next;
    }
    return NULL;
}

void av_bitstream_filter_close(AVBitStreamFilterContext *bsfc){
    av_freep(&bsfc->priv_data);
    av_parser_close(bsfc->parser);
    av_free(bsfc);
}

int av_bitstream_filter_filter(AVBitStreamFilterContext *bsfc,
                               AVCodecContext *avctx, const char *args,
                     uint8_t **poutbuf, int *poutbuf_size,
                     const uint8_t *buf, int buf_size, int keyframe){
    *poutbuf= (uint8_t *) buf;
    *poutbuf_size= buf_size;
    return bsfc->filter->filter(bsfc, avctx, args, poutbuf, poutbuf_size, buf, buf_size, keyframe);
}

static int dump_extradata(AVBitStreamFilterContext *bsfc, AVCodecContext *avctx, const char *args,
                     uint8_t **poutbuf, int *poutbuf_size,
                     const uint8_t *buf, int buf_size, int keyframe){
    int cmd= args ? *args : 0;
    /* cast to avoid warning about discarding qualifiers */
    if(avctx->extradata){
        if(  (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER) && cmd=='a')
           ||(keyframe && (cmd=='k' || !cmd))
           ||(cmd=='e')
            /*||(? && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_BEGIN)*/){
            int size= buf_size + avctx->extradata_size;
            *poutbuf_size= size;
            *poutbuf= av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);

            memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
            memcpy((*poutbuf) + avctx->extradata_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
            return 1;
        }
    }
    return 0;
}

#ifdef CONFIG_DUMP_EXTRADATA_BSF
AVBitStreamFilter dump_extradata_bsf={
    "dump_extra",
    0,
    dump_extradata,
};
#endif