GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/mpegvideo_parser.c Lines: 114 131 87.0 %
Date: 2019-11-22 03:34:36 Branches: 58 88 65.9 %

Line Branch Exec Source
1
/*
2
 * MPEG-1 / MPEG-2 video parser
3
 * Copyright (c) 2000,2001 Fabrice Bellard
4
 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
5
 *
6
 * This file is part of FFmpeg.
7
 *
8
 * FFmpeg is free software; you can redistribute it and/or
9
 * modify it under the terms of the GNU Lesser General Public
10
 * License as published by the Free Software Foundation; either
11
 * version 2.1 of the License, or (at your option) any later version.
12
 *
13
 * FFmpeg is distributed in the hope that it will be useful,
14
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16
 * Lesser General Public License for more details.
17
 *
18
 * You should have received a copy of the GNU Lesser General Public
19
 * License along with FFmpeg; if not, write to the Free Software
20
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21
 */
22
23
#include "parser.h"
24
#include "mpeg12.h"
25
#include "internal.h"
26
27
struct MpvParseContext {
28
    ParseContext pc;
29
    AVRational frame_rate;
30
    int progressive_sequence;
31
    int width, height;
32
};
33
34
35
8602
static void mpegvideo_extract_headers(AVCodecParserContext *s,
36
                                      AVCodecContext *avctx,
37
                                      const uint8_t *buf, int buf_size)
38
{
39
8602
    struct MpvParseContext *pc = s->priv_data;
40
8602
    const uint8_t *buf_end = buf + buf_size;
41
    uint32_t start_code;
42
    int frame_rate_index, ext_type, bytes_left;
43
    int frame_rate_ext_n, frame_rate_ext_d;
44
    int top_field_first, repeat_first_field, progressive_frame;
45
    int horiz_size_ext, vert_size_ext, bit_rate_ext;
46
8602
    int did_set_size=0;
47
8602
    int set_dim_ret = 0;
48
8602
    int bit_rate = 0;
49
8602
    int vbv_delay = 0;
50
    int chroma_format;
51
8602
    enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
52
//FIXME replace the crap with get_bits()
53
8602
    s->repeat_pict = 0;
54
55
31761
    while (buf < buf_end) {
56
31511
        start_code= -1;
57
31511
        buf= avpriv_find_start_code(buf, buf_end, &start_code);
58
31511
        bytes_left = buf_end - buf;
59

31511
        switch(start_code) {
60
8331
        case PICTURE_START_CODE:
61
8331
            if (bytes_left >= 2) {
62
8331
                s->pict_type = (buf[1] >> 3) & 7;
63
8331
                if (bytes_left >= 4)
64
8331
                    vbv_delay = ((buf[1] & 0x07) << 13) | (buf[2] << 5) | (buf[3] >> 3);
65
            }
66
8331
            break;
67
1920
        case SEQ_START_CODE:
68
1920
            if (bytes_left >= 7) {
69
1920
                pc->width  = (buf[0] << 4) | (buf[1] >> 4);
70
1920
                pc->height = ((buf[1] & 0x0f) << 8) | buf[2];
71


1920
                if(!avctx->width || !avctx->height || !avctx->coded_width || !avctx->coded_height){
72
168
                    set_dim_ret = ff_set_dimensions(avctx, pc->width, pc->height);
73
168
                    did_set_size=1;
74
                }
75
1920
                pix_fmt = AV_PIX_FMT_YUV420P;
76
1920
                frame_rate_index = buf[3] & 0xf;
77
1920
                pc->frame_rate = avctx->framerate = ff_mpeg12_frame_rate_tab[frame_rate_index];
78
1920
                bit_rate = (buf[4]<<10) | (buf[5]<<2) | (buf[6]>>6);
79
1920
                avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
80
1920
                avctx->ticks_per_frame = 1;
81
            }
82
1920
            break;
83
10030
        case EXT_START_CODE:
84
10030
            if (bytes_left >= 1) {
85
10030
                ext_type = (buf[0] >> 4);
86
                switch(ext_type) {
87
1781
                case 0x1: /* sequence extension */
88
1781
                    if (bytes_left >= 6) {
89
1781
                        horiz_size_ext = ((buf[1] & 1) << 1) | (buf[2] >> 7);
90
1781
                        vert_size_ext = (buf[2] >> 5) & 3;
91
1781
                        bit_rate_ext = ((buf[2] & 0x1F)<<7) | (buf[3]>>1);
92
1781
                        frame_rate_ext_n = (buf[5] >> 5) & 3;
93
1781
                        frame_rate_ext_d = (buf[5] & 0x1f);
94
1781
                        pc->progressive_sequence = buf[1] & (1 << 3);
95
1781
                        avctx->has_b_frames= !(buf[5] >> 7);
96
97

1781
                        chroma_format = (buf[1] >> 1) & 3;
98
                        switch (chroma_format) {
99
740
                        case 1: pix_fmt = AV_PIX_FMT_YUV420P; break;
100
1041
                        case 2: pix_fmt = AV_PIX_FMT_YUV422P; break;
101
                        case 3: pix_fmt = AV_PIX_FMT_YUV444P; break;
102
                        }
103
104
1781
                        pc->width  = (pc->width & 0xFFF) | (horiz_size_ext << 12);
105
1781
                        pc->height = (pc->height& 0xFFF) | ( vert_size_ext << 12);
106
1781
                        bit_rate = (bit_rate&0x3FFFF) | (bit_rate_ext << 18);
107
1781
                        if(did_set_size)
108
154
                            set_dim_ret = ff_set_dimensions(avctx, pc->width, pc->height);
109
1781
                        avctx->framerate.num = pc->frame_rate.num * (frame_rate_ext_n + 1);
110
1781
                        avctx->framerate.den = pc->frame_rate.den * (frame_rate_ext_d + 1);
111
1781
                        avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
112
1781
                        avctx->ticks_per_frame = 2;
113
                    }
114
1781
                    break;
115
7459
                case 0x8: /* picture coding extension */
116
7459
                    if (bytes_left >= 5) {
117
7459
                        top_field_first = buf[3] & (1 << 7);
118
7459
                        repeat_first_field = buf[3] & (1 << 1);
119
7459
                        progressive_frame = buf[4] & (1 << 7);
120
121
                        /* check if we must repeat the frame */
122
7459
                        s->repeat_pict = 1;
123
7459
                        if (repeat_first_field) {
124
6
                            if (pc->progressive_sequence) {
125
                                if (top_field_first)
126
                                    s->repeat_pict = 5;
127
                                else
128
                                    s->repeat_pict = 3;
129
6
                            } else if (progressive_frame) {
130
6
                                s->repeat_pict = 2;
131
                            }
132
                        }
133
134

7459
                        if (!pc->progressive_sequence && !progressive_frame) {
135
4081
                            if (top_field_first)
136
1539
                                s->field_order = AV_FIELD_TT;
137
                            else
138
2542
                                s->field_order = AV_FIELD_BB;
139
                        } else
140
3378
                            s->field_order = AV_FIELD_PROGRESSIVE;
141
                    }
142
7459
                    break;
143
                }
144
            }
145
10030
            break;
146
        case -1:
147
            goto the_end;
148
11230
        default:
149
            /* we stop parsing when we encounter a slice. It ensures
150
               that this function takes a negligible amount of time */
151
11230
            if (start_code >= SLICE_MIN_START_CODE &&
152
11230
                start_code <= SLICE_MAX_START_CODE)
153
8352
                goto the_end;
154
2878
            break;
155
        }
156
    }
157
250
 the_end: ;
158
8602
    if (set_dim_ret < 0)
159
        av_log(avctx, AV_LOG_ERROR, "Failed to set dimensions\n");
160
161

8602
    if (avctx->codec_id == AV_CODEC_ID_MPEG2VIDEO && bit_rate) {
162
1781
        avctx->rc_max_rate = 400LL*bit_rate;
163
    }
164
8602
    if (bit_rate &&
165

1920
        ((avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO && bit_rate != 0x3FFFF) || vbv_delay != 0xFFFF)) {
166
1031
        avctx->bit_rate = 400LL*bit_rate;
167
    }
168
169
8602
    if (pix_fmt != AV_PIX_FMT_NONE) {
170
1920
        s->format = pix_fmt;
171
1920
        s->width  = pc->width;
172
1920
        s->height = pc->height;
173
1920
        s->coded_width  = FFALIGN(pc->width,  16);
174
1920
        s->coded_height = FFALIGN(pc->height, 16);
175
    }
176
177
#if FF_API_AVCTX_TIMEBASE
178
8602
    if (avctx->framerate.num)
179
8309
        avctx->time_base = av_inv_q(av_mul_q(avctx->framerate, (AVRational){avctx->ticks_per_frame, 1}));
180
#endif
181
8602
}
182
183
47667
static int mpegvideo_parse(AVCodecParserContext *s,
184
                           AVCodecContext *avctx,
185
                           const uint8_t **poutbuf, int *poutbuf_size,
186
                           const uint8_t *buf, int buf_size)
187
{
188
47667
    struct MpvParseContext *pc1 = s->priv_data;
189
47667
    ParseContext *pc= &pc1->pc;
190
    int next;
191
192
47667
    if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
193
2728
        next= buf_size;
194
    }else{
195
44939
        next= ff_mpeg1_find_frame_end(pc, buf, buf_size, s);
196
197
44939
        if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
198
39065
            *poutbuf = NULL;
199
39065
            *poutbuf_size = 0;
200
39065
            return buf_size;
201
        }
202
203
    }
204
    /* we have a full frame : we just parse the first few MPEG headers
205
       to have the full timing information. The time take by this
206
       function should be negligible for uncorrupted streams */
207
8602
    mpegvideo_extract_headers(s, avctx, buf, buf_size);
208
    ff_dlog(NULL, "pict_type=%d frame_rate=%0.3f repeat_pict=%d\n",
209
            s->pict_type, av_q2d(avctx->framerate), s->repeat_pict);
210
211
8602
    *poutbuf = buf;
212
8602
    *poutbuf_size = buf_size;
213
8602
    return next;
214
}
215
216
static int mpegvideo_split(AVCodecContext *avctx,
217
                           const uint8_t *buf, int buf_size)
218
{
219
    int i;
220
    uint32_t state= -1;
221
    int found=0;
222
223
    for(i=0; i<buf_size; i++){
224
        state= (state<<8) | buf[i];
225
        if(state == 0x1B3){
226
            found=1;
227
        }else if(found && state != 0x1B5 && state < 0x200 && state >= 0x100)
228
            return i-3;
229
    }
230
    return 0;
231
}
232
233
657
static int mpegvideo_parse_init(AVCodecParserContext *s)
234
{
235
657
    s->pict_type = AV_PICTURE_TYPE_NONE; // first frame might be partial
236
657
    return 0;
237
}
238
239
AVCodecParser ff_mpegvideo_parser = {
240
    .codec_ids      = { AV_CODEC_ID_MPEG1VIDEO, AV_CODEC_ID_MPEG2VIDEO },
241
    .priv_data_size = sizeof(struct MpvParseContext),
242
    .parser_init    = mpegvideo_parse_init,
243
    .parser_parse   = mpegvideo_parse,
244
    .parser_close   = ff_parse_close,
245
    .split          = mpegvideo_split,
246
};