Revision 7f50d4ac libavcodec/mpeg12.c

View differences:

libavcodec/mpeg12.c
37 37
//#include <assert.h>
38 38

  
39 39

  
40
/* Start codes. */
41
#define SEQ_END_CODE            0x000001b7
42
#define SEQ_START_CODE          0x000001b3
43
#define GOP_START_CODE          0x000001b8
44
#define PICTURE_START_CODE      0x00000100
45
#define SLICE_MIN_START_CODE    0x00000101
46
#define SLICE_MAX_START_CODE    0x000001af
47
#define EXT_START_CODE          0x000001b5
48
#define USER_START_CODE         0x000001b2
49

  
50 40
#define DC_VLC_BITS 9
51 41
#define MV_VLC_BITS 9
52 42
#define MBINCR_VLC_BITS 9
......
3042 3032
 * finds the end of the current frame in the bitstream.
3043 3033
 * @return the position of the first byte of the next frame, or -1
3044 3034
 */
3045
static int mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
3035
int mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
3046 3036
{
3047 3037
    int i;
3048 3038
    uint32_t state= pc->state;
......
3364 3354

  
3365 3355
#endif
3366 3356

  
3367
#ifdef CONFIG_MPEGVIDEO_PARSER
3368
static void mpegvideo_extract_headers(AVCodecParserContext *s,
3369
                                      AVCodecContext *avctx,
3370
                                      const uint8_t *buf, int buf_size)
3371
{
3372
    ParseContext1 *pc = s->priv_data;
3373
    const uint8_t *buf_end;
3374
    uint32_t start_code;
3375
    int frame_rate_index, ext_type, bytes_left;
3376
    int frame_rate_ext_n, frame_rate_ext_d;
3377
    int picture_structure, top_field_first, repeat_first_field, progressive_frame;
3378
    int horiz_size_ext, vert_size_ext, bit_rate_ext;
3379
//FIXME replace the crap with get_bits()
3380
    s->repeat_pict = 0;
3381
    buf_end = buf + buf_size;
3382
    while (buf < buf_end) {
3383
        start_code= -1;
3384
        buf= ff_find_start_code(buf, buf_end, &start_code);
3385
        bytes_left = buf_end - buf;
3386
        switch(start_code) {
3387
        case PICTURE_START_CODE:
3388
            if (bytes_left >= 2) {
3389
                s->pict_type = (buf[1] >> 3) & 7;
3390
            }
3391
            break;
3392
        case SEQ_START_CODE:
3393
            if (bytes_left >= 7) {
3394
                pc->width  = (buf[0] << 4) | (buf[1] >> 4);
3395
                pc->height = ((buf[1] & 0x0f) << 8) | buf[2];
3396
                avcodec_set_dimensions(avctx, pc->width, pc->height);
3397
                frame_rate_index = buf[3] & 0xf;
3398
                pc->frame_rate.den = avctx->time_base.den = ff_frame_rate_tab[frame_rate_index].num;
3399
                pc->frame_rate.num = avctx->time_base.num = ff_frame_rate_tab[frame_rate_index].den;
3400
                avctx->bit_rate = ((buf[4]<<10) | (buf[5]<<2) | (buf[6]>>6))*400;
3401
                avctx->codec_id = CODEC_ID_MPEG1VIDEO;
3402
                avctx->sub_id = 1;
3403
            }
3404
            break;
3405
        case EXT_START_CODE:
3406
            if (bytes_left >= 1) {
3407
                ext_type = (buf[0] >> 4);
3408
                switch(ext_type) {
3409
                case 0x1: /* sequence extension */
3410
                    if (bytes_left >= 6) {
3411
                        horiz_size_ext = ((buf[1] & 1) << 1) | (buf[2] >> 7);
3412
                        vert_size_ext = (buf[2] >> 5) & 3;
3413
                        bit_rate_ext = ((buf[2] & 0x1F)<<7) | (buf[3]>>1);
3414
                        frame_rate_ext_n = (buf[5] >> 5) & 3;
3415
                        frame_rate_ext_d = (buf[5] & 0x1f);
3416
                        pc->progressive_sequence = buf[1] & (1 << 3);
3417
                        avctx->has_b_frames= !(buf[5] >> 7);
3418

  
3419
                        pc->width  |=(horiz_size_ext << 12);
3420
                        pc->height |=( vert_size_ext << 12);
3421
                        avctx->bit_rate += (bit_rate_ext << 18) * 400;
3422
                        avcodec_set_dimensions(avctx, pc->width, pc->height);
3423
                        avctx->time_base.den = pc->frame_rate.den * (frame_rate_ext_n + 1);
3424
                        avctx->time_base.num = pc->frame_rate.num * (frame_rate_ext_d + 1);
3425
                        avctx->codec_id = CODEC_ID_MPEG2VIDEO;
3426
                        avctx->sub_id = 2; /* forces MPEG2 */
3427
                    }
3428
                    break;
3429
                case 0x8: /* picture coding extension */
3430
                    if (bytes_left >= 5) {
3431
                        picture_structure = buf[2]&3;
3432
                        top_field_first = buf[3] & (1 << 7);
3433
                        repeat_first_field = buf[3] & (1 << 1);
3434
                        progressive_frame = buf[4] & (1 << 7);
3435

  
3436
                        /* check if we must repeat the frame */
3437
                        if (repeat_first_field) {
3438
                            if (pc->progressive_sequence) {
3439
                                if (top_field_first)
3440
                                    s->repeat_pict = 4;
3441
                                else
3442
                                    s->repeat_pict = 2;
3443
                            } else if (progressive_frame) {
3444
                                s->repeat_pict = 1;
3445
                            }
3446
                        }
3447

  
3448
                        /* the packet only represents half a frame
3449
                           XXX,FIXME maybe find a different solution */
3450
                        if(picture_structure != 3)
3451
                            s->repeat_pict = -1;
3452
                    }
3453
                    break;
3454
                }
3455
            }
3456
            break;
3457
        case -1:
3458
            goto the_end;
3459
        default:
3460
            /* we stop parsing when we encounter a slice. It ensures
3461
               that this function takes a negligible amount of time */
3462
            if (start_code >= SLICE_MIN_START_CODE &&
3463
                start_code <= SLICE_MAX_START_CODE)
3464
                goto the_end;
3465
            break;
3466
        }
3467
    }
3468
 the_end: ;
3469
}
3470

  
3471
static int mpegvideo_parse(AVCodecParserContext *s,
3472
                           AVCodecContext *avctx,
3473
                           uint8_t **poutbuf, int *poutbuf_size,
3474
                           const uint8_t *buf, int buf_size)
3475
{
3476
    ParseContext1 *pc1 = s->priv_data;
3477
    ParseContext *pc= &pc1->pc;
3478
    int next;
3479

  
3480
    if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
3481
        next= buf_size;
3482
    }else{
3483
        next= mpeg1_find_frame_end(pc, buf, buf_size);
3484

  
3485
        if (ff_combine_frame(pc, next, (uint8_t **)&buf, &buf_size) < 0) {
3486
            *poutbuf = NULL;
3487
            *poutbuf_size = 0;
3488
            return buf_size;
3489
        }
3490

  
3491
    }
3492
    /* we have a full frame : we just parse the first few MPEG headers
3493
       to have the full timing information. The time take by this
3494
       function should be negligible for uncorrupted streams */
3495
    mpegvideo_extract_headers(s, avctx, buf, buf_size);
3496
#if 0
3497
    printf("pict_type=%d frame_rate=%0.3f repeat_pict=%d\n",
3498
           s->pict_type, (double)avctx->time_base.den / avctx->time_base.num, s->repeat_pict);
3499
#endif
3500

  
3501
    *poutbuf = (uint8_t *)buf;
3502
    *poutbuf_size = buf_size;
3503
    return next;
3504
}
3505

  
3506
static int mpegvideo_split(AVCodecContext *avctx,
3507
                           const uint8_t *buf, int buf_size)
3508
{
3509
    int i;
3510
    uint32_t state= -1;
3511

  
3512
    for(i=0; i<buf_size; i++){
3513
        state= (state<<8) | buf[i];
3514
        if(state != 0x1B3 && state != 0x1B5 && state < 0x200 && state >= 0x100)
3515
            return i-3;
3516
    }
3517
    return 0;
3518
}
3519

  
3520
AVCodecParser mpegvideo_parser = {
3521
    { CODEC_ID_MPEG1VIDEO, CODEC_ID_MPEG2VIDEO },
3522
    sizeof(ParseContext1),
3523
    NULL,
3524
    mpegvideo_parse,
3525
    ff_parse1_close,
3526
    mpegvideo_split,
3527
};
3528
#endif /* !CONFIG_MPEGVIDEO_PARSER */
3529

  
3530 3357
static int imx_dump_header(AVBitStreamFilterContext *bsfc, AVCodecContext *avctx, const char *args,
3531 3358
                           uint8_t **poutbuf, int *poutbuf_size,
3532 3359
                           const uint8_t *buf, int buf_size, int keyframe)

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