PeerStreamer

/*

 * FLV decoding.

 * 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 "mpegvideo.h"

#include "h263.h"

#include "flv.h"

#include "libavutil/imgutils.h"

void ff_flv2_decode_ac_esc(GetBitContext *gb, int *level, int *run, int *last){

    int is11 = get_bits1(gb);

    *last = get_bits1(gb);

    *run = get_bits(gb, 6);

    if(is11){

        *level = get_sbits(gb, 11);

    } else {

        *level = get_sbits(gb, 7);

    }

}

int ff_flv_decode_picture_header(MpegEncContext *s)

{

    int format, width, height;

    /* picture header */

    if (get_bits_long(&s->gb, 17) != 1) {

        av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");

        return -1;

    }

    format = get_bits(&s->gb, 5);

    if (format != 0 && format != 1) {

        av_log(s->avctx, AV_LOG_ERROR, "Bad picture format\n");

        return -1;

    }

    s->h263_flv = format+1;

    s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */

    format = get_bits(&s->gb, 3);

    switch (format) {

    case 0:

        width = get_bits(&s->gb, 8);

        height = get_bits(&s->gb, 8);

        break;

    case 1:

        width = get_bits(&s->gb, 16);

        height = get_bits(&s->gb, 16);

        break;

    case 2:

        width = 352;

        height = 288;

        break;

    case 3:

        width = 176;

        height = 144;

        break;

    case 4:

        width = 128;

        height = 96;

        break;

    case 5:

        width = 320;

        height = 240;

        break;

    case 6:

        width = 160;

        height = 120;

        break;

    default:

        width = height = 0;

        break;

    }

    if(av_image_check_size(width, height, 0, s->avctx))

        return -1;

    s->width = width;

    s->height = height;

    s->pict_type = AV_PICTURE_TYPE_I + get_bits(&s->gb, 2);

    s->dropable= s->pict_type > AV_PICTURE_TYPE_P;

    if (s->dropable)

        s->pict_type = AV_PICTURE_TYPE_P;

    skip_bits1(&s->gb); /* deblocking flag */

    s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);

    s->h263_plus = 0;

    s->unrestricted_mv = 1;

    s->h263_long_vectors = 0;

    /* PEI */

    while (get_bits1(&s->gb) != 0) {

        skip_bits(&s->gb, 8);

    }

    s->f_code = 1;

    if(s->avctx->debug & FF_DEBUG_PICT_INFO){

        av_log(s->avctx, AV_LOG_DEBUG, "%c esc_type:%d, qp:%d num:%d\n",

               s->dropable ? 'D' : av_get_picture_type_char(s->pict_type), s->h263_flv-1, s->qscale, s->picture_number);

    }

    s->y_dc_scale_table=

    s->c_dc_scale_table= ff_mpeg1_dc_scale_table;

    return 0;

}

AVCodec ff_flv_decoder = {

    "flv",

    AVMEDIA_TYPE_VIDEO,

    CODEC_ID_FLV1,

    sizeof(MpegEncContext),

    ff_h263_decode_init,

    NULL,

    ff_h263_decode_end,

    ff_h263_decode_frame,

    CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,

    .max_lowres= 3,

    .long_name= NULL_IF_CONFIG_SMALL("Flash Video (FLV) / Sorenson Spark / Sorenson H.263"),

    .pix_fmts= ff_pixfmt_list_420,

};