summaryrefslogtreecommitdiffstats
path: root/libavformat/yuv4mpegdec.c
blob: e5c4456ed7348b992523b1ce2125fd36119fda5e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/*
 * YUV4MPEG demuxer
 * Copyright (c) 2001, 2002, 2003 Fabrice Bellard
 *
 * This file is part of Libav.
 *
 * Libav 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.
 *
 * Libav 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 Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "avformat.h"
#include "internal.h"
#include "yuv4mpeg.h"

/* Header size increased to allow room for optional flags */
#define MAX_YUV4_HEADER 80
#define MAX_FRAME_HEADER 80

static int yuv4_read_header(AVFormatContext *s)
{
    char header[MAX_YUV4_HEADER + 10];  // Include headroom for
                                        // the longest option
    char *tokstart, *tokend, *header_end;
    int i;
    AVIOContext *pb = s->pb;
    int width = -1, height  = -1, raten   = 0,
        rated =  0, aspectn =  0, aspectd = 0;
    enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE, alt_pix_fmt = AV_PIX_FMT_NONE;
    enum AVChromaLocation chroma_sample_location = AVCHROMA_LOC_UNSPECIFIED;
    AVStream *st;
    enum AVFieldOrder field_order;

    for (i = 0; i < MAX_YUV4_HEADER; i++) {
        header[i] = avio_r8(pb);
        if (header[i] == '\n') {
            header[i + 1] = 0x20;  // Add a space after last option.
                                   // Makes parsing "444" vs "444alpha" easier.
            header[i + 2] = 0;
            break;
        }
    }
    if (i == MAX_YUV4_HEADER)
        return -1;
    if (strncmp(header, Y4M_MAGIC, strlen(Y4M_MAGIC)))
        return -1;

    header_end = &header[i + 1]; // Include space
    for (tokstart = &header[strlen(Y4M_MAGIC) + 1];
         tokstart < header_end; tokstart++) {
        if (*tokstart == 0x20)
            continue;
        switch (*tokstart++) {
        case 'W': // Width. Required.
            width    = strtol(tokstart, &tokend, 10);
            tokstart = tokend;
            break;
        case 'H': // Height. Required.
            height   = strtol(tokstart, &tokend, 10);
            tokstart = tokend;
            break;
        case 'C': // Color space
            if (strncmp("420jpeg", tokstart, 7) == 0) {
                pix_fmt = AV_PIX_FMT_YUV420P;
                chroma_sample_location = AVCHROMA_LOC_CENTER;
            } else if (strncmp("420mpeg2", tokstart, 8) == 0) {
                pix_fmt = AV_PIX_FMT_YUV420P;
                chroma_sample_location = AVCHROMA_LOC_LEFT;
            } else if (strncmp("420paldv", tokstart, 8) == 0) {
                pix_fmt = AV_PIX_FMT_YUV420P;
                chroma_sample_location = AVCHROMA_LOC_TOPLEFT;
            } else if (strncmp("420", tokstart, 3) == 0) {
                pix_fmt = AV_PIX_FMT_YUV420P;
                chroma_sample_location = AVCHROMA_LOC_CENTER;
            } else if (strncmp("411", tokstart, 3) == 0)
                pix_fmt = AV_PIX_FMT_YUV411P;
            else if (strncmp("422", tokstart, 3) == 0)
                pix_fmt = AV_PIX_FMT_YUV422P;
            else if (strncmp("444alpha", tokstart, 8) == 0 ) {
                av_log(s, AV_LOG_ERROR, "Cannot handle 4:4:4:4 "
                       "YUV4MPEG stream.\n");
                return -1;
            } else if (strncmp("444", tokstart, 3) == 0)
                pix_fmt = AV_PIX_FMT_YUV444P;
            else if (strncmp("mono", tokstart, 4) == 0) {
                pix_fmt = AV_PIX_FMT_GRAY8;
            } else {
                av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains an unknown "
                       "pixel format.\n");
                return -1;
            }
            while (tokstart < header_end && *tokstart != 0x20)
                tokstart++;
            break;
        case 'I': // Interlace type
            switch (*tokstart++){
            case '?':
                field_order = AV_FIELD_UNKNOWN;
                break;
            case 'p':
                field_order = AV_FIELD_PROGRESSIVE;
                break;
            case 't':
                field_order = AV_FIELD_TT;
                break;
            case 'b':
                field_order = AV_FIELD_BB;
                break;
            case 'm':
                av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains mixed "
                       "interlaced and non-interlaced frames.\n");
                return -1;
            default:
                av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");
                return -1;
            }
            break;
        case 'F': // Frame rate
            sscanf(tokstart, "%d:%d", &raten, &rated); // 0:0 if unknown
            while (tokstart < header_end && *tokstart != 0x20)
                tokstart++;
            break;
        case 'A': // Pixel aspect
            sscanf(tokstart, "%d:%d", &aspectn, &aspectd); // 0:0 if unknown
            while (tokstart < header_end && *tokstart != 0x20)
                tokstart++;
            break;
        case 'X': // Vendor extensions
            if (strncmp("YSCSS=", tokstart, 6) == 0) {
                // Older nonstandard pixel format representation
                tokstart += 6;
                if (strncmp("420JPEG", tokstart, 7) == 0)
                    alt_pix_fmt = AV_PIX_FMT_YUV420P;
                else if (strncmp("420MPEG2", tokstart, 8) == 0)
                    alt_pix_fmt = AV_PIX_FMT_YUV420P;
                else if (strncmp("420PALDV", tokstart, 8) == 0)
                    alt_pix_fmt = AV_PIX_FMT_YUV420P;
                else if (strncmp("411", tokstart, 3) == 0)
                    alt_pix_fmt = AV_PIX_FMT_YUV411P;
                else if (strncmp("422", tokstart, 3) == 0)
                    alt_pix_fmt = AV_PIX_FMT_YUV422P;
                else if (strncmp("444", tokstart, 3) == 0)
                    alt_pix_fmt = AV_PIX_FMT_YUV444P;
            }
            while (tokstart < header_end && *tokstart != 0x20)
                tokstart++;
            break;
        }
    }

    if (width == -1 || height == -1) {
        av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");
        return -1;
    }

    if (pix_fmt == AV_PIX_FMT_NONE) {
        if (alt_pix_fmt == AV_PIX_FMT_NONE)
            pix_fmt = AV_PIX_FMT_YUV420P;
        else
            pix_fmt = alt_pix_fmt;
    }

    if (raten <= 0 || rated <= 0) {
        // Frame rate unknown
        raten = 25;
        rated = 1;
    }

    if (aspectn == 0 && aspectd == 0) {
        // Pixel aspect unknown
        aspectd = 1;
    }

    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);
    st->codec->width  = width;
    st->codec->height = height;
    av_reduce(&raten, &rated, raten, rated, (1UL << 31) - 1);
    avpriv_set_pts_info(st, 64, rated, raten);
    st->avg_frame_rate                = av_inv_q(st->time_base);
    st->codec->pix_fmt                = pix_fmt;
    st->codec->codec_type             = AVMEDIA_TYPE_VIDEO;
    st->codec->codec_id               = AV_CODEC_ID_RAWVIDEO;
    st->sample_aspect_ratio           = (AVRational){ aspectn, aspectd };
    st->codec->chroma_sample_location = chroma_sample_location;
    st->codec->field_order            = field_order;

    return 0;
}

static int yuv4_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    int i;
    char header[MAX_FRAME_HEADER+1];
    int packet_size, width, height, ret;
    AVStream *st = s->streams[0];

    for (i = 0; i < MAX_FRAME_HEADER; i++) {
        header[i] = avio_r8(s->pb);
        if (header[i] == '\n') {
            header[i + 1] = 0;
            break;
        }
    }
    if (s->pb->error)
        return s->pb->error;
    else if (s->pb->eof_reached)
        return AVERROR_EOF;
    else if (i == MAX_FRAME_HEADER)
        return AVERROR_INVALIDDATA;

    if (strncmp(header, Y4M_FRAME_MAGIC, strlen(Y4M_FRAME_MAGIC)))
        return AVERROR_INVALIDDATA;

    width  = st->codec->width;
    height = st->codec->height;

    packet_size = avpicture_get_size(st->codec->pix_fmt, width, height);
    if (packet_size < 0)
        return packet_size;

    ret = av_get_packet(s->pb, pkt, packet_size);
    if (ret < 0)
        return ret;
    else if (ret != packet_size)
        return s->pb->eof_reached ? AVERROR_EOF : AVERROR(EIO);

    pkt->stream_index = 0;
    return 0;
}

static int yuv4_probe(AVProbeData *pd)
{
    /* check file header */
    if (strncmp(pd->buf, Y4M_MAGIC, sizeof(Y4M_MAGIC) - 1) == 0)
        return AVPROBE_SCORE_MAX;
    else
        return 0;
}

AVInputFormat ff_yuv4mpegpipe_demuxer = {
    .name           = "yuv4mpegpipe",
    .long_name      = NULL_IF_CONFIG_SMALL("YUV4MPEG pipe"),
    .read_probe     = yuv4_probe,
    .read_header    = yuv4_read_header,
    .read_packet    = yuv4_read_packet,
    .extensions     = "y4m",
};
OpenPOWER on IntegriCloud