| /* |
| * MPEG-4 encoder/decoder internal header. |
| * Copyright (c) 2000,2001 Fabrice Bellard |
| * Copyright (c) 2002-2010 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 |
| */ |
| |
| #ifndef AVCODEC_MPEG4VIDEO_H |
| #define AVCODEC_MPEG4VIDEO_H |
| |
| #include <stdint.h> |
| |
| #include "mpegvideo.h" |
| |
| void ff_mpeg4_clean_buffers(MpegEncContext *s); |
| int ff_mpeg4_get_video_packet_prefix_length(MpegEncContext *s); |
| void ff_mpeg4_init_direct_mv(MpegEncContext *s); |
| |
| /** |
| * @return the mb_type |
| */ |
| int ff_mpeg4_set_direct_mv(MpegEncContext *s, int mx, int my); |
| |
| #if 0 //3IV1 is quite rare and it slows things down a tiny bit |
| #define IS_3IV1 s->codec_tag == AV_RL32("3IV1") |
| #else |
| #define IS_3IV1 0 |
| #endif |
| |
| /** |
| * Predict the dc. |
| * encoding quantized level -> quantized diff |
| * decoding quantized diff -> quantized level |
| * @param n block index (0-3 are luma, 4-5 are chroma) |
| * @param dir_ptr pointer to an integer where the prediction direction will be stored |
| */ |
| static inline int ff_mpeg4_pred_dc(MpegEncContext *s, int n, int level, |
| int *dir_ptr, int encoding) |
| { |
| int a, b, c, wrap, pred, scale, ret; |
| int16_t *dc_val; |
| |
| /* find prediction */ |
| if (n < 4) |
| scale = s->y_dc_scale; |
| else |
| scale = s->c_dc_scale; |
| if (IS_3IV1) |
| scale = 8; |
| |
| wrap = s->block_wrap[n]; |
| dc_val = s->dc_val[0] + s->block_index[n]; |
| |
| /* B C |
| * A X |
| */ |
| a = dc_val[-1]; |
| b = dc_val[-1 - wrap]; |
| c = dc_val[-wrap]; |
| |
| /* outside slice handling (we can't do that by memset as we need the |
| * dc for error resilience) */ |
| if (s->first_slice_line && n != 3) { |
| if (n != 2) |
| b = c = 1024; |
| if (n != 1 && s->mb_x == s->resync_mb_x) |
| b = a = 1024; |
| } |
| if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1) { |
| if (n == 0 || n == 4 || n == 5) |
| b = 1024; |
| } |
| |
| if (abs(a - b) < abs(b - c)) { |
| pred = c; |
| *dir_ptr = 1; /* top */ |
| } else { |
| pred = a; |
| *dir_ptr = 0; /* left */ |
| } |
| /* we assume pred is positive */ |
| pred = FASTDIV((pred + (scale >> 1)), scale); |
| |
| if (encoding) { |
| ret = level - pred; |
| } else { |
| level += pred; |
| ret = level; |
| } |
| level *= scale; |
| if (level & (~2047)) { |
| if (!s->encoding && (s->avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE))) { |
| if (level < 0) { |
| av_log(s->avctx, AV_LOG_ERROR, |
| "dc<0 at %dx%d\n", s->mb_x, s->mb_y); |
| return AVERROR_INVALIDDATA; |
| } |
| if (level > 2048 + scale) { |
| av_log(s->avctx, AV_LOG_ERROR, |
| "dc overflow at %dx%d\n", s->mb_x, s->mb_y); |
| return AVERROR_INVALIDDATA; |
| } |
| } |
| if (level < 0) |
| level = 0; |
| else if (!(s->workaround_bugs & FF_BUG_DC_CLIP)) |
| level = 2047; |
| } |
| dc_val[0] = level; |
| |
| return ret; |
| } |
| |
| #endif /* AVCODEC_MPEG4VIDEO_H */ |