matroska: Read only the data written in the scratch buffer
[libav.git] / libavformat / yuv4mpegdec.c
1 /*
2 * YUV4MPEG demuxer
3 * Copyright (c) 2001, 2002, 2003 Fabrice Bellard
4 *
5 * This file is part of Libav.
6 *
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include "libavutil/imgutils.h"
23
24 #include "avformat.h"
25 #include "internal.h"
26 #include "yuv4mpeg.h"
27
28 /* Header size increased to allow room for optional flags */
29 #define MAX_YUV4_HEADER 80
30 #define MAX_FRAME_HEADER 80
31
32 static int yuv4_read_header(AVFormatContext *s)
33 {
34 char header[MAX_YUV4_HEADER + 10]; // Include headroom for
35 // the longest option
36 char *tokstart, *tokend, *header_end;
37 int i;
38 AVIOContext *pb = s->pb;
39 int width = -1, height = -1, raten = 0,
40 rated = 0, aspectn = 0, aspectd = 0;
41 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE, alt_pix_fmt = AV_PIX_FMT_NONE;
42 enum AVChromaLocation chroma_sample_location = AVCHROMA_LOC_UNSPECIFIED;
43 enum AVFieldOrder field_order = AV_FIELD_UNKNOWN;
44 AVStream *st;
45
46 for (i = 0; i < MAX_YUV4_HEADER; i++) {
47 header[i] = avio_r8(pb);
48 if (header[i] == '\n') {
49 header[i + 1] = 0x20; // Add a space after last option.
50 // Makes parsing "444" vs "444alpha" easier.
51 header[i + 2] = 0;
52 break;
53 }
54 }
55 if (i == MAX_YUV4_HEADER)
56 return -1;
57 if (strncmp(header, Y4M_MAGIC, strlen(Y4M_MAGIC)))
58 return -1;
59
60 header_end = &header[i + 1]; // Include space
61 for (tokstart = &header[strlen(Y4M_MAGIC) + 1];
62 tokstart < header_end; tokstart++) {
63 if (*tokstart == 0x20)
64 continue;
65 switch (*tokstart++) {
66 case 'W': // Width. Required.
67 width = strtol(tokstart, &tokend, 10);
68 tokstart = tokend;
69 break;
70 case 'H': // Height. Required.
71 height = strtol(tokstart, &tokend, 10);
72 tokstart = tokend;
73 break;
74 case 'C': // Color space
75 if (strncmp("420jpeg", tokstart, 7) == 0) {
76 pix_fmt = AV_PIX_FMT_YUV420P;
77 chroma_sample_location = AVCHROMA_LOC_CENTER;
78 } else if (strncmp("420mpeg2", tokstart, 8) == 0) {
79 pix_fmt = AV_PIX_FMT_YUV420P;
80 chroma_sample_location = AVCHROMA_LOC_LEFT;
81 } else if (strncmp("420paldv", tokstart, 8) == 0) {
82 pix_fmt = AV_PIX_FMT_YUV420P;
83 chroma_sample_location = AVCHROMA_LOC_TOPLEFT;
84 } else if (strncmp("420", tokstart, 3) == 0) {
85 pix_fmt = AV_PIX_FMT_YUV420P;
86 chroma_sample_location = AVCHROMA_LOC_CENTER;
87 } else if (strncmp("411", tokstart, 3) == 0)
88 pix_fmt = AV_PIX_FMT_YUV411P;
89 else if (strncmp("422", tokstart, 3) == 0)
90 pix_fmt = AV_PIX_FMT_YUV422P;
91 else if (strncmp("444alpha", tokstart, 8) == 0 ) {
92 av_log(s, AV_LOG_ERROR, "Cannot handle 4:4:4:4 "
93 "YUV4MPEG stream.\n");
94 return -1;
95 } else if (strncmp("444", tokstart, 3) == 0)
96 pix_fmt = AV_PIX_FMT_YUV444P;
97 else if (strncmp("mono", tokstart, 4) == 0) {
98 pix_fmt = AV_PIX_FMT_GRAY8;
99 } else {
100 av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains an unknown "
101 "pixel format.\n");
102 return -1;
103 }
104 while (tokstart < header_end && *tokstart != 0x20)
105 tokstart++;
106 break;
107 case 'I': // Interlace type
108 switch (*tokstart++){
109 case '?':
110 field_order = AV_FIELD_UNKNOWN;
111 break;
112 case 'p':
113 field_order = AV_FIELD_PROGRESSIVE;
114 break;
115 case 't':
116 field_order = AV_FIELD_TT;
117 break;
118 case 'b':
119 field_order = AV_FIELD_BB;
120 break;
121 case 'm':
122 av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains mixed "
123 "interlaced and non-interlaced frames.\n");
124 return -1;
125 default:
126 av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");
127 return -1;
128 }
129 break;
130 case 'F': // Frame rate
131 sscanf(tokstart, "%d:%d", &raten, &rated); // 0:0 if unknown
132 while (tokstart < header_end && *tokstart != 0x20)
133 tokstart++;
134 break;
135 case 'A': // Pixel aspect
136 sscanf(tokstart, "%d:%d", &aspectn, &aspectd); // 0:0 if unknown
137 while (tokstart < header_end && *tokstart != 0x20)
138 tokstart++;
139 break;
140 case 'X': // Vendor extensions
141 if (strncmp("YSCSS=", tokstart, 6) == 0) {
142 // Older nonstandard pixel format representation
143 tokstart += 6;
144 if (strncmp("420JPEG", tokstart, 7) == 0)
145 alt_pix_fmt = AV_PIX_FMT_YUV420P;
146 else if (strncmp("420MPEG2", tokstart, 8) == 0)
147 alt_pix_fmt = AV_PIX_FMT_YUV420P;
148 else if (strncmp("420PALDV", tokstart, 8) == 0)
149 alt_pix_fmt = AV_PIX_FMT_YUV420P;
150 else if (strncmp("411", tokstart, 3) == 0)
151 alt_pix_fmt = AV_PIX_FMT_YUV411P;
152 else if (strncmp("422", tokstart, 3) == 0)
153 alt_pix_fmt = AV_PIX_FMT_YUV422P;
154 else if (strncmp("444", tokstart, 3) == 0)
155 alt_pix_fmt = AV_PIX_FMT_YUV444P;
156 }
157 while (tokstart < header_end && *tokstart != 0x20)
158 tokstart++;
159 break;
160 }
161 }
162
163 if (width == -1 || height == -1) {
164 av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");
165 return -1;
166 }
167
168 if (pix_fmt == AV_PIX_FMT_NONE) {
169 if (alt_pix_fmt == AV_PIX_FMT_NONE)
170 pix_fmt = AV_PIX_FMT_YUV420P;
171 else
172 pix_fmt = alt_pix_fmt;
173 }
174
175 if (raten <= 0 || rated <= 0) {
176 // Frame rate unknown
177 raten = 25;
178 rated = 1;
179 }
180
181 if (aspectn == 0 && aspectd == 0) {
182 // Pixel aspect unknown
183 aspectd = 1;
184 }
185
186 st = avformat_new_stream(s, NULL);
187 if (!st)
188 return AVERROR(ENOMEM);
189 st->codecpar->width = width;
190 st->codecpar->height = height;
191 av_reduce(&raten, &rated, raten, rated, (1UL << 31) - 1);
192 avpriv_set_pts_info(st, 64, rated, raten);
193 st->avg_frame_rate = av_inv_q(st->time_base);
194 st->codecpar->format = pix_fmt;
195 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
196 st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
197 st->sample_aspect_ratio = (AVRational){ aspectn, aspectd };
198 st->codecpar->chroma_location = chroma_sample_location;
199 st->codecpar->field_order = field_order;
200
201 return 0;
202 }
203
204 static int yuv4_read_packet(AVFormatContext *s, AVPacket *pkt)
205 {
206 int i;
207 char header[MAX_FRAME_HEADER+1];
208 int packet_size, width, height, ret;
209 AVStream *st = s->streams[0];
210
211 for (i = 0; i < MAX_FRAME_HEADER; i++) {
212 header[i] = avio_r8(s->pb);
213 if (header[i] == '\n') {
214 header[i + 1] = 0;
215 break;
216 }
217 }
218 if (s->pb->error)
219 return s->pb->error;
220 else if (s->pb->eof_reached)
221 return AVERROR_EOF;
222 else if (i == MAX_FRAME_HEADER)
223 return AVERROR_INVALIDDATA;
224
225 if (strncmp(header, Y4M_FRAME_MAGIC, strlen(Y4M_FRAME_MAGIC)))
226 return AVERROR_INVALIDDATA;
227
228 width = st->codecpar->width;
229 height = st->codecpar->height;
230
231 packet_size = av_image_get_buffer_size(st->codecpar->format,
232 width, height, 1);
233 if (packet_size < 0)
234 return packet_size;
235
236 ret = av_get_packet(s->pb, pkt, packet_size);
237 if (ret < 0)
238 return ret;
239 else if (ret != packet_size)
240 return s->pb->eof_reached ? AVERROR_EOF : AVERROR(EIO);
241
242 pkt->stream_index = 0;
243 return 0;
244 }
245
246 static int yuv4_probe(AVProbeData *pd)
247 {
248 /* check file header */
249 if (strncmp(pd->buf, Y4M_MAGIC, sizeof(Y4M_MAGIC) - 1) == 0)
250 return AVPROBE_SCORE_MAX;
251 else
252 return 0;
253 }
254
255 AVInputFormat ff_yuv4mpegpipe_demuxer = {
256 .name = "yuv4mpegpipe",
257 .long_name = NULL_IF_CONFIG_SMALL("YUV4MPEG pipe"),
258 .read_probe = yuv4_probe,
259 .read_header = yuv4_read_header,
260 .read_packet = yuv4_read_packet,
261 .extensions = "y4m",
262 };