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/*

 * DV decoder

 * Copyright (c) 2002 Fabrice Bellard

 * Copyright (c) 2004 Roman Shaposhnik

 *

 * 50 Mbps (DVCPRO50) support

 * Copyright (c) 2006 Daniel Maas 

 *

 * 100 Mbps (DVCPRO HD) support

 * Initial code by Daniel Maas  (funded by BBC R&D)

 * Final code by Roman Shaposhnik

 *

 * Many thanks to Dan Dennedy  for providing wealth

 * of DV technical info.

 *

 * 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

 */

/**

 * @file

 * DV decoder

 */

#include "libavutil/avassert.h"

#include "libavutil/internal.h"

#include "libavutil/pixdesc.h"

#include "avcodec.h"

#include "internal.h"

#include "get_bits.h"

#include "put_bits.h"

#include "simple_idct.h"

#include "dvdata.h"

typedef struct BlockInfo {

    const uint32_t *factor_table;

    const uint8_t *scan_table;

    uint8_t pos; /* position in block */

    void (*idct_put)(uint8_t *dest, int line_size, int16_t *block);

    uint8_t partial_bit_count;

    uint32_t partial_bit_buffer;

    int shift_offset;

} BlockInfo;

static const int dv_iweight_bits = 14;

/* decode AC coefficients */

static void dv_decode_ac(GetBitContext *gb, BlockInfo *mb, int16_t *block)

{

    int last_index = gb->size_in_bits;

    const uint8_t  *scan_table   = mb->scan_table;

    const uint32_t *factor_table = mb->factor_table;

    int pos               = mb->pos;

    int partial_bit_count = mb->partial_bit_count;

    int level, run, vlc_len, index;

    OPEN_READER(re, gb);

    UPDATE_CACHE(re, gb);

    /* if we must parse a partial VLC, we do it here */

    if (partial_bit_count > 0) {

        re_cache = re_cache >> partial_bit_count | mb->partial_bit_buffer;

        re_index -= partial_bit_count;

        mb->partial_bit_count = 0;

    }

    /* get the AC coefficients until last_index is reached */

    for (;;) {

        av_dlog(NULL, "%2d: bits=%04x index=%d\n", pos, SHOW_UBITS(re, gb, 16),

                re_index);

        /* our own optimized GET_RL_VLC */

        index   = NEG_USR32(re_cache, TEX_VLC_BITS);

        vlc_len = ff_dv_rl_vlc[index].len;

        if (vlc_len < 0) {

            index = NEG_USR32((unsigned)re_cache << TEX_VLC_BITS, -vlc_len) +

                    ff_dv_rl_vlc[index].level;

            vlc_len = TEX_VLC_BITS - vlc_len;

        }

        level = ff_dv_rl_vlc[index].level;

        run   = ff_dv_rl_vlc[index].run;

        /* gotta check if we're still within gb boundaries */

        if (re_index + vlc_len > last_index) {

            /* should be < 16 bits otherwise a codeword could have been parsed */

            mb->partial_bit_count = last_index - re_index;

            mb->partial_bit_buffer = re_cache & ~(-1u >> mb->partial_bit_count);

            re_index = last_index;

            break;

        }

        re_index += vlc_len;

        av_dlog(NULL, "run=%d level=%d\n", run, level);

        pos += run;

        if (pos >= 64)

            break;

        level = (level * factor_table[pos] + (1 << (dv_iweight_bits - 1))) >> dv_iweight_bits;

        block[scan_table[pos]] = level;

        UPDATE_CACHE(re, gb);

    }

    CLOSE_READER(re, gb);

    mb->pos = pos;

}

static inline void bit_copy(PutBitContext *pb, GetBitContext *gb)

{

    int bits_left = get_bits_left(gb);

    while (bits_left >= MIN_CACHE_BITS) {

        put_bits(pb, MIN_CACHE_BITS, get_bits(gb, MIN_CACHE_BITS));

        bits_left -= MIN_CACHE_BITS;

    }

    if (bits_left > 0) {

        put_bits(pb, bits_left, get_bits(gb, bits_left));

    }

}

/* mb_x and mb_y are in units of 8 pixels */

static int dv_decode_video_segment(AVCodecContext *avctx, void *arg)

{

    DVVideoContext *s = avctx->priv_data;

    DVwork_chunk *work_chunk = arg;

    int quant, dc, dct_mode, class1, j;

    int mb_index, mb_x, mb_y, last_index;

    int y_stride, linesize;

    int16_t *block, *block1;

    int c_offset;

    uint8_t *y_ptr;

    const uint8_t *buf_ptr;

    PutBitContext pb, vs_pb;

    GetBitContext gb;

    BlockInfo mb_data[5 * DV_MAX_BPM], *mb, *mb1;

    LOCAL_ALIGNED_16(int16_t, sblock, [5*DV_MAX_BPM], [64]);

    LOCAL_ALIGNED_16(uint8_t, mb_bit_buffer, [  80 + FF_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */

    LOCAL_ALIGNED_16(uint8_t, vs_bit_buffer, [5*80 + FF_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */

    const int log2_blocksize = 3-s->avctx->lowres;

    int is_field_mode[5];

    av_assert1((((int)mb_bit_buffer) & 7) == 0);

    av_assert1((((int)vs_bit_buffer) & 7) == 0);

    memset(sblock, 0, 5*DV_MAX_BPM*sizeof(*sblock));

    /* pass 1: read DC and AC coefficients in blocks */

    buf_ptr = &s->buf[work_chunk->buf_offset*80];

    block1  = &sblock[0][0];

    mb1     = mb_data;

    init_put_bits(&vs_pb, vs_bit_buffer, 5 * 80);

    for (mb_index = 0; mb_index < 5; mb_index++, mb1 += s->sys->bpm, block1 += s->sys->bpm * 64) {

        /* skip header */

        quant = buf_ptr[3] & 0x0f;

        buf_ptr += 4;

        init_put_bits(&pb, mb_bit_buffer, 80);

        mb    = mb1;

        block = block1;

        is_field_mode[mb_index] = 0;

        for (j = 0; j < s->sys->bpm; j++) {

            last_index = s->sys->block_sizes[j];

            init_get_bits(&gb, buf_ptr, last_index);

            /* get the DC */

            dc       = get_sbits(&gb, 9);

            dct_mode = get_bits1(&gb);

            class1   = get_bits(&gb, 2);

            if (DV_PROFILE_IS_HD(s->sys)) {

                mb->idct_put     = s->idct_put[0];

                mb->scan_table   = s->dv_zigzag[0];

                mb->factor_table = &s->sys->idct_factor[(j >= 4)*4*16*64 + class1*16*64 + quant*64];

                is_field_mode[mb_index] |= !j && dct_mode;

            } else {

                mb->idct_put     = s->idct_put[dct_mode && log2_blocksize == 3];

                mb->scan_table   = s->dv_zigzag[dct_mode];

                mb->factor_table = &s->sys->idct_factor[(class1 == 3)*2*22*64 + dct_mode*22*64 +

                                                        (quant + ff_dv_quant_offset[class1])*64];

            }

            dc = dc << 2;

            /* convert to unsigned because 128 is not added in the

               standard IDCT */

            dc += 1024;

            block[0] = dc;

            buf_ptr += last_index >> 3;

            mb->pos               = 0;

            mb->partial_bit_count = 0;

            av_dlog(avctx, "MB block: %d, %d ", mb_index, j);

            dv_decode_ac(&gb, mb, block);

            /* write the remaining bits in a new buffer only if the

               block is finished */

            if (mb->pos >= 64)

                bit_copy(&pb, &gb);

            block += 64;

            mb++;

        }

        /* pass 2: we can do it just after */

        av_dlog(avctx, "***pass 2 size=%d MB#=%d\n", put_bits_count(&pb), mb_index);

        block = block1;

        mb    = mb1;

        init_get_bits(&gb, mb_bit_buffer, put_bits_count(&pb));

        put_bits32(&pb, 0); // padding must be zeroed

        flush_put_bits(&pb);

        for (j = 0; j < s->sys->bpm; j++, block += 64, mb++) {

            if (mb->pos < 64 && get_bits_left(&gb) > 0) {

                dv_decode_ac(&gb, mb, block);

                /* if still not finished, no need to parse other blocks */

                if (mb->pos < 64)

                    break;

            }

        }

        /* all blocks are finished, so the extra bytes can be used at

           the video segment level */

        if (j >= s->sys->bpm)

            bit_copy(&vs_pb, &gb);

    }

    /* we need a pass over the whole video segment */

    av_dlog(avctx, "***pass 3 size=%d\n", put_bits_count(&vs_pb));

    block = &sblock[0][0];

    mb    = mb_data;

    init_get_bits(&gb, vs_bit_buffer, put_bits_count(&vs_pb));

    put_bits32(&vs_pb, 0); // padding must be zeroed

    flush_put_bits(&vs_pb);

    for (mb_index = 0; mb_index < 5; mb_index++) {

        for (j = 0; j < s->sys->bpm; j++) {

            if (mb->pos < 64) {

                av_dlog(avctx, "start %d:%d\n", mb_index, j);

                dv_decode_ac(&gb, mb, block);

            }

            if (mb->pos >= 64 && mb->pos < 127)

                av_log(avctx, AV_LOG_ERROR, "AC EOB marker is absent pos=%d\n", mb->pos);

            block += 64;

            mb++;

        }

    }

    /* compute idct and place blocks */

    block = &sblock[0][0];

    mb    = mb_data;

    for (mb_index = 0; mb_index < 5; mb_index++) {

        dv_calculate_mb_xy(s, work_chunk, mb_index, &mb_x, &mb_y);

        /* idct_put'ting luminance */

        if ((s->sys->pix_fmt == AV_PIX_FMT_YUV420P) ||

            (s->sys->pix_fmt == AV_PIX_FMT_YUV411P && mb_x >= (704 / 8)) ||

            (s->sys->height >= 720 && mb_y != 134)) {

            y_stride = (s->picture.linesize[0] << ((!is_field_mode[mb_index]) * log2_blocksize));

        } else {

            y_stride = (2 << log2_blocksize);

        }

        y_ptr = s->picture.data[0] + ((mb_y * s->picture.linesize[0] + mb_x) << log2_blocksize);

        linesize = s->picture.linesize[0] << is_field_mode[mb_index];

        mb[0]    .idct_put(y_ptr                                   , linesize, block + 0*64);

        if (s->sys->video_stype == 4) { /* SD 422 */

            mb[2].idct_put(y_ptr + (1 << log2_blocksize)           , linesize, block + 2*64);

        } else {

            mb[1].idct_put(y_ptr + (1 << log2_blocksize)           , linesize, block + 1*64);

            mb[2].idct_put(y_ptr                         + y_stride, linesize, block + 2*64);

            mb[3].idct_put(y_ptr + (1 << log2_blocksize) + y_stride, linesize, block + 3*64);

        }

        mb += 4;

        block += 4*64;

        /* idct_put'ting chrominance */

        c_offset = (((mb_y >>  (s->sys->pix_fmt == AV_PIX_FMT_YUV420P)) * s->picture.linesize[1] +

                     (mb_x >> ((s->sys->pix_fmt == AV_PIX_FMT_YUV411P) ? 2 : 1))) << log2_blocksize);

        for (j = 2; j; j--) {

            uint8_t *c_ptr = s->picture.data[j] + c_offset;

            if (s->sys->pix_fmt == AV_PIX_FMT_YUV411P && mb_x >= (704 / 8)) {

                  uint64_t aligned_pixels[64/8];

                  uint8_t *pixels = (uint8_t*)aligned_pixels;

                  uint8_t *c_ptr1, *ptr1;

                  int x, y;

                  mb->idct_put(pixels, 8, block);

                  for (y = 0; y < (1 << log2_blocksize); y++, c_ptr += s->picture.linesize[j], pixels += 8) {

                      ptr1   = pixels + ((1 << (log2_blocksize))>>1);

                      c_ptr1 = c_ptr + (s->picture.linesize[j] << log2_blocksize);

                      for (x = 0; x < (1 << FFMAX(log2_blocksize - 1, 0)); x++) {

                          c_ptr[x]  = pixels[x];

                          c_ptr1[x] = ptr1[x];

                      }

                  }

                  block += 64; mb++;

            } else {

                  y_stride = (mb_y == 134) ? (1 << log2_blocksize) :

                                             s->picture.linesize[j] << ((!is_field_mode[mb_index]) * log2_blocksize);

                  linesize = s->picture.linesize[j] << is_field_mode[mb_index];

                  (mb++)->    idct_put(c_ptr           , linesize, block); block += 64;

                  if (s->sys->bpm == 8) {

                      (mb++)->idct_put(c_ptr + y_stride, linesize, block); block += 64;

                  }

            }

        }

    }

    return 0;

}

/* NOTE: exactly one frame must be given (120000 bytes for NTSC,

   144000 bytes for PAL - or twice those for 50Mbps) */

static int dvvideo_decode_frame(AVCodecContext *avctx,

                                 void *data, int *got_frame,

                                 AVPacket *avpkt)

{

    uint8_t *buf = avpkt->data;

    int buf_size = avpkt->size;

    DVVideoContext *s = avctx->priv_data;

    const uint8_t* vsc_pack;

    int ret, apt, is16_9;

    s->sys = avpriv_dv_frame_profile2(avctx, s->sys, buf, buf_size);

    if (!s->sys || buf_size < s->sys->frame_size || ff_dv_init_dynamic_tables(s->sys)) {

        av_log(avctx, AV_LOG_ERROR, "could not find dv frame profile\n");

        return -1; /* NOTE: we only accept several full frames */

    }

    s->picture.key_frame = 1;

    s->picture.pict_type = AV_PICTURE_TYPE_I;

    avctx->pix_fmt   = s->sys->pix_fmt;

    avctx->time_base = s->sys->time_base;

    avcodec_set_dimensions(avctx, s->sys->width, s->sys->height);

    if ((ret = ff_get_buffer(avctx, &s->picture, 0)) < 0)

        return ret;

    s->picture.interlaced_frame = 1;

    s->picture.top_field_first  = 0;

    /* Determine the codec's sample_aspect ratio and field order from the packet */

    vsc_pack = buf + 80*5 + 48 + 5;

    if ( *vsc_pack == dv_video_control ) {

        apt = buf[4] & 0x07;

        is16_9 = (vsc_pack[2] & 0x07) == 0x02 || (!apt && (vsc_pack[2] & 0x07) == 0x07);

        avctx->sample_aspect_ratio = s->sys->sar[is16_9];

        s->picture.top_field_first = !(vsc_pack[3] & 0x40);

    }

    s->buf = buf;

    avctx->execute(avctx, dv_decode_video_segment, s->sys->work_chunks, NULL,

                   dv_work_pool_size(s->sys), sizeof(DVwork_chunk));

    emms_c();

    /* return image */

    *got_frame = 1;

    av_frame_move_ref(data, &s->picture);

    return s->sys->frame_size;

}

static int dvvideo_close(AVCodecContext *c)

{

    DVVideoContext *s = c->priv_data;

    av_frame_unref(&s->picture);

    return 0;

}

AVCodec ff_dvvideo_decoder = {

    .name           = "dvvideo",

    .long_name      = NULL_IF_CONFIG_SMALL("DV (Digital Video)"),

    .type           = AVMEDIA_TYPE_VIDEO,

    .id             = AV_CODEC_ID_DVVIDEO,

    .priv_data_size = sizeof(DVVideoContext),

    .init           = ff_dvvideo_init,

    .close          = dvvideo_close,

    .decode         = dvvideo_decode_frame,

    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_SLICE_THREADS,

    .max_lowres     = 3,

};