FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/mdec.c
Date: 2026-01-23 19:11:46
Exec Total Coverage
Lines: 106 112 94.6%
Functions: 6 6 100.0%
Branches: 30 36 83.3%
Line Branch Exec Source
1 /*
2 * Sony PlayStation MDEC (Motion DECoder)
3 * Copyright (c) 2003 Michael Niedermayer
4 *
5 * based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl>
6 *
7 * This file is part of FFmpeg.
8 *
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.
13 *
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.
18 *
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
22 */
23
24 /**
25 * @file
26 * Sony PlayStation MDEC (Motion DECoder)
27 * This is very similar to intra-only MPEG-1.
28 */
29
30 #include "libavutil/mem.h"
31 #include "libavutil/mem_internal.h"
32
33 #include "avcodec.h"
34 #include "blockdsp.h"
35 #include "bswapdsp.h"
36 #include "codec_internal.h"
37 #include "idctdsp.h"
38 #include "mpeg12data.h"
39 #include "mpeg12dec.h"
40 #include "thread.h"
41
42 typedef struct MDECContext {
43 AVCodecContext *avctx;
44 BlockDSPContext bdsp;
45 BswapDSPContext bbdsp;
46 IDCTDSPContext idsp;
47 GetBitContext gb;
48 uint8_t permutated_scantable[64];
49 int version;
50 int qscale;
51 int last_dc[3];
52 int mb_width;
53 int mb_height;
54 int mb_x, mb_y;
55 DECLARE_ALIGNED(32, int16_t, block)[6][64];
56 DECLARE_ALIGNED(16, uint16_t, quant_matrix)[64];
57 uint8_t *bitstream_buffer;
58 unsigned int bitstream_buffer_size;
59 } MDECContext;
60
61 //very similar to MPEG-1
62 285689 static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
63 {
64 int level, diff, i, j, run;
65 int component;
66 285689 const uint8_t *const scantable = a->permutated_scantable;
67 285689 const uint16_t *quant_matrix = a->quant_matrix;
68 285689 const int qscale = a->qscale;
69
70 /* DC coefficient */
71
2/2
✓ Branch 0 taken 214889 times.
✓ Branch 1 taken 70800 times.
 285689 if (a->version <= 2) {
72 214889 block[0] = 2 * get_sbits(&a->gb, 10) + 1024;
73 } else {
74 70800 component = (n <= 3 ? 0 : n - 4 + 1);
75 70800 diff = decode_dc(&a->gb, component);
76 70800 a->last_dc[component] += diff;
77 70800 block[0] = a->last_dc[component] * (1 << 3);
78 }
79
80 285689 i = 0;
81 {
82 285689 OPEN_READER(re, &a->gb);
83 /* now quantify & encode AC coefficients */
84 for (;;) {
85 4638889 UPDATE_CACHE(re, &a->gb);
86
2/2
✓ Branch 1 taken 250831 times.
✓ Branch 2 taken 2211458 times.
 2462289 GET_RL_VLC(level, run, re, &a->gb, ff_mpeg1_rl_vlc, TEX_VLC_BITS, 2, 0);
87
88
2/2
✓ Branch 0 taken 285688 times.
✓ Branch 1 taken 2176601 times.
 2462289 if (level == 127) {
89 285688 break;
90
2/2
✓ Branch 0 taken 2133703 times.
✓ Branch 1 taken 42898 times.
 2176601 } else if (level != 0) {
91 2133703 i += run;
92
2/2
✓ Branch 0 taken 1 times.
✓ Branch 1 taken 2133702 times.
 2133703 if (i > 63) {
93 1 av_log(a->avctx, AV_LOG_ERROR,
94 "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
95 1 return AVERROR_INVALIDDATA;
96 }
97 2133702 j = scantable[i];
98 2133702 level = (level * qscale * quant_matrix[j]) >> 3;
99 2133702 level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
100 2133702 LAST_SKIP_BITS(re, &a->gb, 1);
101 } else {
102 /* escape */
103 42898 run = SHOW_UBITS(re, &a->gb, 6) + 1;
104 42898 SKIP_BITS(re, &a->gb, 6);
105 42898 level = SHOW_SBITS(re, &a->gb, 10);
106 42898 LAST_SKIP_BITS(re, &a->gb, 10);
107 42898 i += run;
108
1/2
✗ Branch 0 not taken.
✓ Branch 1 taken 42898 times.
 42898 if (i > 63) {
109 ✗ av_log(a->avctx, AV_LOG_ERROR,
110 "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
111 ✗ return AVERROR_INVALIDDATA;
112 }
113 42898 j = scantable[i];
114
2/2
✓ Branch 0 taken 24818 times.
✓ Branch 1 taken 18080 times.
 42898 if (level < 0) {
115 24818 level = -level;
116 24818 level = (level * (unsigned)qscale * quant_matrix[j]) >> 3;
117 24818 level = (level - 1) | 1;
118 24818 level = -level;
119 } else {
120 18080 level = (level * (unsigned)qscale * quant_matrix[j]) >> 3;
121 18080 level = (level - 1) | 1;
122 }
123 }
124
125 2176600 block[j] = level;
126 }
127 285688 CLOSE_READER(re, &a->gb);
128 }
129 285688 return 0;
130 }
131
132 47615 static inline int decode_mb(MDECContext *a, int16_t block[6][64])
133 {
134 int i, ret;
135 static const int block_index[6] = { 5, 4, 0, 1, 2, 3 };
136
137 47615 a->bdsp.clear_blocks(block[0]);
138
139
2/2
✓ Branch 0 taken 285689 times.
✓ Branch 1 taken 47614 times.
 333303 for (i = 0; i < 6; i++) {
140
2/2
✓ Branch 0 taken 1 times.
✓ Branch 1 taken 285688 times.
 285689 if ((ret = mdec_decode_block_intra(a, block[block_index[i]],
141 285689 block_index[i])) < 0)
142 1 return ret;
143
1/2
✗ Branch 1 not taken.
✓ Branch 2 taken 285688 times.
 285688 if (get_bits_left(&a->gb) < 0)
144 ✗ return AVERROR_INVALIDDATA;
145 }
146 47614 return 0;
147 }
148
149 47614 static inline void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)
150 {
151 47614 int16_t (*block)[64] = a->block;
152 47614 int linesize = frame->linesize[0];
153
154 47614 uint8_t *dest_y = frame->data[0] + (mb_y * 16* linesize ) + mb_x * 16;
155 47614 uint8_t *dest_cb = frame->data[1] + (mb_y * 8 * frame->linesize[1]) + mb_x * 8;
156 47614 uint8_t *dest_cr = frame->data[2] + (mb_y * 8 * frame->linesize[2]) + mb_x * 8;
157
158 47614 a->idsp.idct_put(dest_y, linesize, block[0]);
159 47614 a->idsp.idct_put(dest_y + 8, linesize, block[1]);
160 47614 a->idsp.idct_put(dest_y + 8 * linesize, linesize, block[2]);
161 47614 a->idsp.idct_put(dest_y + 8 * linesize + 8, linesize, block[3]);
162
163
1/2
✓ Branch 0 taken 47614 times.
✗ Branch 1 not taken.
 47614 if (!(a->avctx->flags & AV_CODEC_FLAG_GRAY)) {
164 47614 a->idsp.idct_put(dest_cb, frame->linesize[1], block[4]);
165 47614 a->idsp.idct_put(dest_cr, frame->linesize[2], block[5]);
166 }
167 47614 }
168
169 194 static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
170 int *got_frame, AVPacket *avpkt)
171 {
172 194 MDECContext * const a = avctx->priv_data;
173 194 const uint8_t *buf = avpkt->data;
174 194 int buf_size = avpkt->size;
175 int ret;
176
177
1/2
✗ Branch 1 not taken.
✓ Branch 2 taken 194 times.
 194 if ((ret = ff_thread_get_buffer(avctx, frame, 0)) < 0)
178 ✗ return ret;
179
180 194 av_fast_padded_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size);
181
1/2
✗ Branch 0 not taken.
✓ Branch 1 taken 194 times.
 194 if (!a->bitstream_buffer)
182 ✗ return AVERROR(ENOMEM);
183 194 a->bbdsp.bswap16_buf((uint16_t *)a->bitstream_buffer, (uint16_t *)buf, (buf_size + 1) / 2);
184
1/2
✗ Branch 1 not taken.
✓ Branch 2 taken 194 times.
 194 if ((ret = init_get_bits8(&a->gb, a->bitstream_buffer, buf_size)) < 0)
185 ✗ return ret;
186
187 /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
188 194 skip_bits(&a->gb, 32);
189
190 194 a->qscale = get_bits(&a->gb, 16);
191 194 a->version = get_bits(&a->gb, 16);
192
193 194 a->last_dc[0] = a->last_dc[1] = a->last_dc[2] = 128;
194
195
2/2
✓ Branch 0 taken 3739 times.
✓ Branch 1 taken 193 times.
 3932 for (a->mb_x = 0; a->mb_x < a->mb_width; a->mb_x++) {
196
2/2
✓ Branch 0 taken 47615 times.
✓ Branch 1 taken 3738 times.
 51353 for (a->mb_y = 0; a->mb_y < a->mb_height; a->mb_y++) {
197
2/2
✓ Branch 1 taken 1 times.
✓ Branch 2 taken 47614 times.
 47615 if ((ret = decode_mb(a, a->block)) < 0)
198 1 return ret;
199
200 47614 idct_put(a, frame, a->mb_x, a->mb_y);
201 }
202 }
203
204 193 *got_frame = 1;
205
206 193 return (get_bits_count(&a->gb) + 31) / 32 * 4;
207 }
208
209 7 static av_cold int decode_init(AVCodecContext *avctx)
210 {
211 7 MDECContext * const a = avctx->priv_data;
212 int i;
213
214 7 a->mb_width = (avctx->coded_width + 15) / 16;
215 7 a->mb_height = (avctx->coded_height + 15) / 16;
216
217 7 a->avctx = avctx;
218
219 7 ff_blockdsp_init(&a->bdsp);
220 7 ff_bswapdsp_init(&a->bbdsp);
221 7 ff_idctdsp_init(&a->idsp, avctx);
222 7 ff_mpeg12_init_vlcs();
223 7 ff_permute_scantable(a->permutated_scantable, ff_zigzag_direct,
224 7 a->idsp.idct_permutation);
225
226 7 avctx->pix_fmt = AV_PIX_FMT_YUVJ420P;
227 7 avctx->color_range = AVCOL_RANGE_JPEG;
228
229 /* init q matrix */
230
2/2
✓ Branch 0 taken 448 times.
✓ Branch 1 taken 7 times.
 455 for (i = 0; i < 64; i++) {
231 448 int j = a->idsp.idct_permutation[i];
232
233 448 a->quant_matrix[j] = ff_mpeg1_default_intra_matrix[i];
234 }
235
236 7 return 0;
237 }
238
239 7 static av_cold int decode_end(AVCodecContext *avctx)
240 {
241 7 MDECContext * const a = avctx->priv_data;
242
243 7 av_freep(&a->bitstream_buffer);
244 7 a->bitstream_buffer_size = 0;
245
246 7 return 0;
247 }
248
249 const FFCodec ff_mdec_decoder = {
250 .p.name = "mdec",
251 CODEC_LONG_NAME("Sony PlayStation MDEC (Motion DECoder)"),
252 .p.type = AVMEDIA_TYPE_VIDEO,
253 .p.id = AV_CODEC_ID_MDEC,
254 .priv_data_size = sizeof(MDECContext),
255 .init = decode_init,
256 .close = decode_end,
257 FF_CODEC_DECODE_CB(decode_frame),
258 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
259 };
260