yading@10: /*
yading@10:  * Electronic Arts Madcow Video Decoder
yading@10:  * Copyright (c) 2007-2009 Peter Ross
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * Electronic Arts Madcow Video Decoder
yading@10:  * @author Peter Ross <pross@xvid.org>
yading@10:  *
yading@10:  * @see technical details at
yading@10:  * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_MAD
yading@10:  */
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #include "get_bits.h"
yading@10: #include "aandcttab.h"
yading@10: #include "eaidct.h"
yading@10: #include "internal.h"
yading@10: #include "mpeg12.h"
yading@10: #include "mpeg12data.h"
yading@10: #include "libavutil/imgutils.h"
yading@10: 
yading@10: #define EA_PREAMBLE_SIZE    8
yading@10: #define MADk_TAG MKTAG('M', 'A', 'D', 'k')    /* MAD i-frame */
yading@10: #define MADm_TAG MKTAG('M', 'A', 'D', 'm')    /* MAD p-frame */
yading@10: #define MADe_TAG MKTAG('M', 'A', 'D', 'e')    /* MAD lqp-frame */
yading@10: 
yading@10: typedef struct MadContext {
yading@10:     AVCodecContext *avctx;
yading@10:     DSPContext dsp;
yading@10:     AVFrame last_frame;
yading@10:     GetBitContext gb;
yading@10:     void *bitstream_buf;
yading@10:     unsigned int bitstream_buf_size;
yading@10:     DECLARE_ALIGNED(16, int16_t, block)[64];
yading@10:     ScanTable scantable;
yading@10:     uint16_t quant_matrix[64];
yading@10:     int mb_x;
yading@10:     int mb_y;
yading@10: } MadContext;
yading@10: 
yading@10: static av_cold int decode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     MadContext *s = avctx->priv_data;
yading@10:     s->avctx = avctx;
yading@10:     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
yading@10:     ff_dsputil_init(&s->dsp, avctx);
yading@10:     ff_init_scantable_permutation(s->dsp.idct_permutation, FF_NO_IDCT_PERM);
yading@10:     ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
yading@10:     ff_mpeg12_init_vlcs();
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static inline void comp(unsigned char *dst, int dst_stride,
yading@10:                         unsigned char *src, int src_stride, int add)
yading@10: {
yading@10:     int j, i;
yading@10:     for (j=0; j<8; j++)
yading@10:         for (i=0; i<8; i++)
yading@10:             dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
yading@10: }
yading@10: 
yading@10: static inline void comp_block(MadContext *t, AVFrame *frame,
yading@10:                               int mb_x, int mb_y,
yading@10:                               int j, int mv_x, int mv_y, int add)
yading@10: {
yading@10:     if (j < 4) {
yading@10:         unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame.linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x;
yading@10:         if (offset >= (t->avctx->height - 7) * t->last_frame.linesize[0] - 7)
yading@10:             return;
yading@10:         comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
yading@10:              frame->linesize[0],
yading@10:              t->last_frame.data[0] + offset,
yading@10:              t->last_frame.linesize[0], add);
yading@10:     } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
yading@10:         int index = j - 3;
yading@10:         unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame.linesize[index] + mb_x * 8 + (mv_x/2);
yading@10:         if (offset >= (t->avctx->height/2 - 7) * t->last_frame.linesize[index] - 7)
yading@10:             return;
yading@10:         comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
yading@10:              frame->linesize[index],
yading@10:              t->last_frame.data[index] + offset,
yading@10:              t->last_frame.linesize[index], add);
yading@10:     }
yading@10: }
yading@10: 
yading@10: static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
yading@10:                             int mb_x, int mb_y, int j)
yading@10: {
yading@10:     if (j < 4) {
yading@10:         ff_ea_idct_put_c(
yading@10:             frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
yading@10:             frame->linesize[0], block);
yading@10:     } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
yading@10:         int index = j - 3;
yading@10:         ff_ea_idct_put_c(
yading@10:             frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
yading@10:             frame->linesize[index], block);
yading@10:     }
yading@10: }
yading@10: 
yading@10: static inline int decode_block_intra(MadContext *s, int16_t * block)
yading@10: {
yading@10:     int level, i, j, run;
yading@10:     RLTable *rl = &ff_rl_mpeg1;
yading@10:     const uint8_t *scantable = s->scantable.permutated;
yading@10:     int16_t *quant_matrix = s->quant_matrix;
yading@10: 
yading@10:     block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
yading@10: 
yading@10:     /* The RL decoder is derived from mpeg1_decode_block_intra;
yading@10:        Escaped level and run values a decoded differently */
yading@10:     i = 0;
yading@10:     {
yading@10:         OPEN_READER(re, &s->gb);
yading@10:         /* now quantify & encode AC coefficients */
yading@10:         for (;;) {
yading@10:             UPDATE_CACHE(re, &s->gb);
yading@10:             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
yading@10: 
yading@10:             if (level == 127) {
yading@10:                 break;
yading@10:             } else if (level != 0) {
yading@10:                 i += run;
yading@10:                 j = scantable[i];
yading@10:                 level = (level*quant_matrix[j]) >> 4;
yading@10:                 level = (level-1)|1;
yading@10:                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
yading@10:                 LAST_SKIP_BITS(re, &s->gb, 1);
yading@10:             } else {
yading@10:                 /* escape */
yading@10:                 UPDATE_CACHE(re, &s->gb);
yading@10:                 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
yading@10: 
yading@10:                 UPDATE_CACHE(re, &s->gb);
yading@10:                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
yading@10: 
yading@10:                 i += run;
yading@10:                 j = scantable[i];
yading@10:                 if (level < 0) {
yading@10:                     level = -level;
yading@10:                     level = (level*quant_matrix[j]) >> 4;
yading@10:                     level = (level-1)|1;
yading@10:                     level = -level;
yading@10:                 } else {
yading@10:                     level = (level*quant_matrix[j]) >> 4;
yading@10:                     level = (level-1)|1;
yading@10:                 }
yading@10:             }
yading@10:             if (i > 63) {
yading@10:                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
yading@10:                 return -1;
yading@10:             }
yading@10: 
yading@10:             block[j] = level;
yading@10:         }
yading@10:         CLOSE_READER(re, &s->gb);
yading@10:     }
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int decode_motion(GetBitContext *gb)
yading@10: {
yading@10:     int value = 0;
yading@10:     if (get_bits1(gb)) {
yading@10:         if (get_bits1(gb))
yading@10:             value = -17;
yading@10:         value += get_bits(gb, 4) + 1;
yading@10:     }
yading@10:     return value;
yading@10: }
yading@10: 
yading@10: static int decode_mb(MadContext *s, AVFrame *frame, int inter)
yading@10: {
yading@10:     int mv_map = 0;
yading@10:     int mv_x, mv_y;
yading@10:     int j;
yading@10: 
yading@10:     if (inter) {
yading@10:         int v = decode210(&s->gb);
yading@10:         if (v < 2) {
yading@10:             mv_map = v ? get_bits(&s->gb, 6) : 63;
yading@10:             mv_x = decode_motion(&s->gb);
yading@10:             mv_y = decode_motion(&s->gb);
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     for (j=0; j<6; j++) {
yading@10:         if (mv_map & (1<<j)) {  // mv_x and mv_y are guarded by mv_map
yading@10:             int add = 2*decode_motion(&s->gb);
yading@10:             if (s->last_frame.data[0])
yading@10:                 comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
yading@10:         } else {
yading@10:             s->dsp.clear_block(s->block);
yading@10:             if(decode_block_intra(s, s->block) < 0)
yading@10:                 return -1;
yading@10:             idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
yading@10:         }
yading@10:     }
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static void calc_quant_matrix(MadContext *s, int qscale)
yading@10: {
yading@10:     int i;
yading@10: 
yading@10:     s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
yading@10:     for (i=1; i<64; i++)
yading@10:         s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
yading@10: }
yading@10: 
yading@10: static int decode_frame(AVCodecContext *avctx,
yading@10:                         void *data, int *got_frame,
yading@10:                         AVPacket *avpkt)
yading@10: {
yading@10:     const uint8_t *buf = avpkt->data;
yading@10:     int buf_size       = avpkt->size;
yading@10:     const uint8_t *buf_end = buf+buf_size;
yading@10:     MadContext *s     = avctx->priv_data;
yading@10:     AVFrame *frame    = data;
yading@10:     int width, height;
yading@10:     int chunk_type;
yading@10:     int inter, ret;
yading@10: 
yading@10:     if (buf_size < 26) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n");
yading@10:         *got_frame = 0;
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     chunk_type = AV_RL32(&buf[0]);
yading@10:     inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
yading@10:     buf += 8;
yading@10: 
yading@10:     av_reduce(&avctx->time_base.num, &avctx->time_base.den,
yading@10:               AV_RL16(&buf[6]), 1000, 1<<30);
yading@10: 
yading@10:     width  = AV_RL16(&buf[8]);
yading@10:     height = AV_RL16(&buf[10]);
yading@10:     calc_quant_matrix(s, buf[13]);
yading@10:     buf += 16;
yading@10: 
yading@10:     if (avctx->width != width || avctx->height != height) {
yading@10:         if((width * height)/2048*7 > buf_end-buf)
yading@10:             return AVERROR_INVALIDDATA;
yading@10:         if ((ret = av_image_check_size(width, height, 0, avctx)) < 0)
yading@10:             return ret;
yading@10:         avcodec_set_dimensions(avctx, width, height);
yading@10:         av_frame_unref(&s->last_frame);
yading@10:     }
yading@10: 
yading@10:     if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     if (inter && !s->last_frame.data[0]) {
yading@10:         av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
yading@10:         ret = ff_get_buffer(avctx, &s->last_frame, AV_GET_BUFFER_FLAG_REF);
yading@10:         if (ret < 0)
yading@10:             return ret;
yading@10:         memset(s->last_frame.data[0], 0, s->last_frame.height *
yading@10:                s->last_frame.linesize[0]);
yading@10:         memset(s->last_frame.data[1], 0x80, s->last_frame.height / 2 *
yading@10:                s->last_frame.linesize[1]);
yading@10:         memset(s->last_frame.data[2], 0x80, s->last_frame.height / 2 *
yading@10:                s->last_frame.linesize[2]);
yading@10:     }
yading@10: 
yading@10:     av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
yading@10:                           buf_end - buf);
yading@10:     if (!s->bitstream_buf)
yading@10:         return AVERROR(ENOMEM);
yading@10:     s->dsp.bswap16_buf(s->bitstream_buf, (const uint16_t*)buf, (buf_end-buf)/2);
yading@10:     memset((uint8_t*)s->bitstream_buf + (buf_end-buf), 0, FF_INPUT_BUFFER_PADDING_SIZE);
yading@10:     init_get_bits(&s->gb, s->bitstream_buf, 8*(buf_end-buf));
yading@10: 
yading@10:     for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
yading@10:         for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
yading@10:             if(decode_mb(s, frame, inter) < 0)
yading@10:                 return AVERROR_INVALIDDATA;
yading@10: 
yading@10:     *got_frame = 1;
yading@10: 
yading@10:     if (chunk_type != MADe_TAG) {
yading@10:         av_frame_unref(&s->last_frame);
yading@10:         if ((ret = av_frame_ref(&s->last_frame, frame)) < 0)
yading@10:             return ret;
yading@10:     }
yading@10: 
yading@10:     return buf_size;
yading@10: }
yading@10: 
yading@10: static av_cold int decode_end(AVCodecContext *avctx)
yading@10: {
yading@10:     MadContext *t = avctx->priv_data;
yading@10:     av_frame_unref(&t->last_frame);
yading@10:     av_free(t->bitstream_buf);
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: AVCodec ff_eamad_decoder = {
yading@10:     .name           = "eamad",
yading@10:     .type           = AVMEDIA_TYPE_VIDEO,
yading@10:     .id             = AV_CODEC_ID_MAD,
yading@10:     .priv_data_size = sizeof(MadContext),
yading@10:     .init           = decode_init,
yading@10:     .close          = decode_end,
yading@10:     .decode         = decode_frame,
yading@10:     .capabilities   = CODEC_CAP_DR1,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video")
yading@10: };