2 * Sony PlayStation MDEC (Motion DECoder)
3 * Copyright (c) 2003 Michael Niedermayer
5 * based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl>
7 * This file is part of FFmpeg.
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 * Sony PlayStation MDEC (Motion DECoder)
27 * This is very similar to intra-only MPEG-1.
31 #include "mpegvideo.h"
35 typedef struct MDECContext {
36 AVCodecContext *avctx;
47 DECLARE_ALIGNED(16, int16_t, block)[6][64];
48 uint8_t *bitstream_buffer;
49 unsigned int bitstream_buffer_size;
50 int block_last_index[6];
53 //very similar to MPEG-1
54 static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
56 int level, diff, i, j, run;
58 RLTable *rl = &ff_rl_mpeg1;
59 uint8_t * const scantable = a->scantable.permutated;
60 const uint16_t *quant_matrix = ff_mpeg1_default_intra_matrix;
61 const int qscale = a->qscale;
64 if (a->version == 2) {
65 block[0] = 2 * get_sbits(&a->gb, 10) + 1024;
67 component = (n <= 3 ? 0 : n - 4 + 1);
68 diff = decode_dc(&a->gb, component);
70 return AVERROR_INVALIDDATA;
71 a->last_dc[component] += diff;
72 block[0] = a->last_dc[component] << 3;
77 OPEN_READER(re, &a->gb);
78 /* now quantify & encode AC coefficients */
80 UPDATE_CACHE(re, &a->gb);
81 GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
85 } else if (level != 0) {
88 level = (level * qscale * quant_matrix[j]) >> 3;
89 level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
90 LAST_SKIP_BITS(re, &a->gb, 1);
93 run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
94 UPDATE_CACHE(re, &a->gb);
95 level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
100 level = (level * qscale * quant_matrix[j]) >> 3;
101 level = (level - 1) | 1;
104 level = (level * qscale * quant_matrix[j]) >> 3;
105 level = (level - 1) | 1;
109 av_log(a->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
110 return AVERROR_INVALIDDATA;
115 CLOSE_READER(re, &a->gb);
117 a->block_last_index[n] = i;
121 static inline int decode_mb(MDECContext *a, int16_t block[6][64])
124 static const int block_index[6] = { 5, 4, 0, 1, 2, 3 };
126 a->dsp.clear_blocks(block[0]);
128 for (i = 0; i < 6; i++) {
129 if ((ret = mdec_decode_block_intra(a, block[block_index[i]],
130 block_index[i])) < 0)
132 if (get_bits_left(&a->gb) < 0)
133 return AVERROR_INVALIDDATA;
138 static inline void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)
140 int16_t (*block)[64] = a->block;
141 int linesize = frame->linesize[0];
143 uint8_t *dest_y = frame->data[0] + (mb_y * 16* linesize ) + mb_x * 16;
144 uint8_t *dest_cb = frame->data[1] + (mb_y * 8 * frame->linesize[1]) + mb_x * 8;
145 uint8_t *dest_cr = frame->data[2] + (mb_y * 8 * frame->linesize[2]) + mb_x * 8;
147 a->dsp.idct_put(dest_y, linesize, block[0]);
148 a->dsp.idct_put(dest_y + 8, linesize, block[1]);
149 a->dsp.idct_put(dest_y + 8 * linesize, linesize, block[2]);
150 a->dsp.idct_put(dest_y + 8 * linesize + 8, linesize, block[3]);
152 if (!(a->avctx->flags & CODEC_FLAG_GRAY)) {
153 a->dsp.idct_put(dest_cb, frame->linesize[1], block[4]);
154 a->dsp.idct_put(dest_cr, frame->linesize[2], block[5]);
158 static int decode_frame(AVCodecContext *avctx,
159 void *data, int *got_frame,
162 MDECContext * const a = avctx->priv_data;
163 const uint8_t *buf = avpkt->data;
164 int buf_size = avpkt->size;
165 ThreadFrame frame = { .f = data };
168 if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
170 frame.f->pict_type = AV_PICTURE_TYPE_I;
171 frame.f->key_frame = 1;
173 av_fast_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
174 if (!a->bitstream_buffer)
175 return AVERROR(ENOMEM);
176 for (i = 0; i < buf_size; i += 2) {
177 a->bitstream_buffer[i] = buf[i + 1];
178 a->bitstream_buffer[i + 1] = buf[i];
180 if ((ret = init_get_bits8(&a->gb, a->bitstream_buffer, buf_size)) < 0)
183 /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
184 skip_bits(&a->gb, 32);
186 a->qscale = get_bits(&a->gb, 16);
187 a->version = get_bits(&a->gb, 16);
189 a->last_dc[0] = a->last_dc[1] = a->last_dc[2] = 128;
191 for (a->mb_x = 0; a->mb_x < a->mb_width; a->mb_x++) {
192 for (a->mb_y = 0; a->mb_y < a->mb_height; a->mb_y++) {
193 if ((ret = decode_mb(a, a->block)) < 0)
196 idct_put(a, frame.f, a->mb_x, a->mb_y);
202 return (get_bits_count(&a->gb) + 31) / 32 * 4;
205 static av_cold int decode_init(AVCodecContext *avctx)
207 MDECContext * const a = avctx->priv_data;
209 a->mb_width = (avctx->coded_width + 15) / 16;
210 a->mb_height = (avctx->coded_height + 15) / 16;
214 ff_dsputil_init(&a->dsp, avctx);
215 ff_mpeg12_init_vlcs();
216 ff_init_scantable(a->dsp.idct_permutation, &a->scantable, ff_zigzag_direct);
218 if (avctx->idct_algo == FF_IDCT_AUTO)
219 avctx->idct_algo = FF_IDCT_SIMPLE;
220 avctx->pix_fmt = AV_PIX_FMT_YUVJ420P;
225 static av_cold int decode_init_thread_copy(AVCodecContext *avctx)
227 MDECContext * const a = avctx->priv_data;
234 static av_cold int decode_end(AVCodecContext *avctx)
236 MDECContext * const a = avctx->priv_data;
238 av_freep(&a->bitstream_buffer);
239 a->bitstream_buffer_size = 0;
244 AVCodec ff_mdec_decoder = {
246 .long_name = NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"),
247 .type = AVMEDIA_TYPE_VIDEO,
248 .id = AV_CODEC_ID_MDEC,
249 .priv_data_size = sizeof(MDECContext),
252 .decode = decode_frame,
253 .capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS,
254 .init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy)