3 * Copyright (c) 2001, 2002, 2003 Fabrice Bellard
5 * This file is part of Libav.
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.
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.
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
26 /* Header size increased to allow room for optional flags */
27 #define MAX_YUV4_HEADER 80
28 #define MAX_FRAME_HEADER 80
30 static int yuv4_read_header(AVFormatContext *s)
32 char header[MAX_YUV4_HEADER + 10]; // Include headroom for
34 char *tokstart, *tokend, *header_end;
36 AVIOContext *pb = s->pb;
37 int width = -1, height = -1, raten = 0,
38 rated = 0, aspectn = 0, aspectd = 0;
39 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE, alt_pix_fmt = AV_PIX_FMT_NONE;
40 enum AVChromaLocation chroma_sample_location = AVCHROMA_LOC_UNSPECIFIED;
42 enum AVFieldOrder field_order;
44 for (i = 0; i < MAX_YUV4_HEADER; i++) {
45 header[i] = avio_r8(pb);
46 if (header[i] == '\n') {
47 header[i + 1] = 0x20; // Add a space after last option.
48 // Makes parsing "444" vs "444alpha" easier.
53 if (i == MAX_YUV4_HEADER)
55 if (strncmp(header, Y4M_MAGIC, strlen(Y4M_MAGIC)))
58 header_end = &header[i + 1]; // Include space
59 for (tokstart = &header[strlen(Y4M_MAGIC) + 1];
60 tokstart < header_end; tokstart++) {
61 if (*tokstart == 0x20)
63 switch (*tokstart++) {
64 case 'W': // Width. Required.
65 width = strtol(tokstart, &tokend, 10);
68 case 'H': // Height. Required.
69 height = strtol(tokstart, &tokend, 10);
72 case 'C': // Color space
73 if (strncmp("420jpeg", tokstart, 7) == 0) {
74 pix_fmt = AV_PIX_FMT_YUV420P;
75 chroma_sample_location = AVCHROMA_LOC_CENTER;
76 } else if (strncmp("420mpeg2", tokstart, 8) == 0) {
77 pix_fmt = AV_PIX_FMT_YUV420P;
78 chroma_sample_location = AVCHROMA_LOC_LEFT;
79 } else if (strncmp("420paldv", tokstart, 8) == 0) {
80 pix_fmt = AV_PIX_FMT_YUV420P;
81 chroma_sample_location = AVCHROMA_LOC_TOPLEFT;
82 } else if (strncmp("420", tokstart, 3) == 0) {
83 pix_fmt = AV_PIX_FMT_YUV420P;
84 chroma_sample_location = AVCHROMA_LOC_CENTER;
85 } else if (strncmp("411", tokstart, 3) == 0)
86 pix_fmt = AV_PIX_FMT_YUV411P;
87 else if (strncmp("422", tokstart, 3) == 0)
88 pix_fmt = AV_PIX_FMT_YUV422P;
89 else if (strncmp("444alpha", tokstart, 8) == 0 ) {
90 av_log(s, AV_LOG_ERROR, "Cannot handle 4:4:4:4 "
91 "YUV4MPEG stream.\n");
93 } else if (strncmp("444", tokstart, 3) == 0)
94 pix_fmt = AV_PIX_FMT_YUV444P;
95 else if (strncmp("mono", tokstart, 4) == 0) {
96 pix_fmt = AV_PIX_FMT_GRAY8;
98 av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains an unknown "
102 while (tokstart < header_end && *tokstart != 0x20)
105 case 'I': // Interlace type
106 switch (*tokstart++){
108 field_order = AV_FIELD_UNKNOWN;
111 field_order = AV_FIELD_PROGRESSIVE;
114 field_order = AV_FIELD_TT;
117 field_order = AV_FIELD_BB;
120 av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains mixed "
121 "interlaced and non-interlaced frames.\n");
124 av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");
128 case 'F': // Frame rate
129 sscanf(tokstart, "%d:%d", &raten, &rated); // 0:0 if unknown
130 while (tokstart < header_end && *tokstart != 0x20)
133 case 'A': // Pixel aspect
134 sscanf(tokstart, "%d:%d", &aspectn, &aspectd); // 0:0 if unknown
135 while (tokstart < header_end && *tokstart != 0x20)
138 case 'X': // Vendor extensions
139 if (strncmp("YSCSS=", tokstart, 6) == 0) {
140 // Older nonstandard pixel format representation
142 if (strncmp("420JPEG", tokstart, 7) == 0)
143 alt_pix_fmt = AV_PIX_FMT_YUV420P;
144 else if (strncmp("420MPEG2", tokstart, 8) == 0)
145 alt_pix_fmt = AV_PIX_FMT_YUV420P;
146 else if (strncmp("420PALDV", tokstart, 8) == 0)
147 alt_pix_fmt = AV_PIX_FMT_YUV420P;
148 else if (strncmp("411", tokstart, 3) == 0)
149 alt_pix_fmt = AV_PIX_FMT_YUV411P;
150 else if (strncmp("422", tokstart, 3) == 0)
151 alt_pix_fmt = AV_PIX_FMT_YUV422P;
152 else if (strncmp("444", tokstart, 3) == 0)
153 alt_pix_fmt = AV_PIX_FMT_YUV444P;
155 while (tokstart < header_end && *tokstart != 0x20)
161 if (width == -1 || height == -1) {
162 av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");
166 if (pix_fmt == AV_PIX_FMT_NONE) {
167 if (alt_pix_fmt == AV_PIX_FMT_NONE)
168 pix_fmt = AV_PIX_FMT_YUV420P;
170 pix_fmt = alt_pix_fmt;
173 if (raten <= 0 || rated <= 0) {
174 // Frame rate unknown
179 if (aspectn == 0 && aspectd == 0) {
180 // Pixel aspect unknown
184 st = avformat_new_stream(s, NULL);
186 return AVERROR(ENOMEM);
187 st->codec->width = width;
188 st->codec->height = height;
189 av_reduce(&raten, &rated, raten, rated, (1UL << 31) - 1);
190 avpriv_set_pts_info(st, 64, rated, raten);
191 st->avg_frame_rate = av_inv_q(st->time_base);
192 st->codec->pix_fmt = pix_fmt;
193 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
194 st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
195 st->sample_aspect_ratio = (AVRational){ aspectn, aspectd };
196 st->codec->chroma_sample_location = chroma_sample_location;
197 st->codec->field_order = field_order;
202 static int yuv4_read_packet(AVFormatContext *s, AVPacket *pkt)
205 char header[MAX_FRAME_HEADER+1];
206 int packet_size, width, height, ret;
207 AVStream *st = s->streams[0];
209 for (i = 0; i < MAX_FRAME_HEADER; i++) {
210 header[i] = avio_r8(s->pb);
211 if (header[i] == '\n') {
218 else if (s->pb->eof_reached)
220 else if (i == MAX_FRAME_HEADER)
221 return AVERROR_INVALIDDATA;
223 if (strncmp(header, Y4M_FRAME_MAGIC, strlen(Y4M_FRAME_MAGIC)))
224 return AVERROR_INVALIDDATA;
226 width = st->codec->width;
227 height = st->codec->height;
229 packet_size = avpicture_get_size(st->codec->pix_fmt, width, height);
233 ret = av_get_packet(s->pb, pkt, packet_size);
236 else if (ret != packet_size)
237 return s->pb->eof_reached ? AVERROR_EOF : AVERROR(EIO);
239 pkt->stream_index = 0;
243 static int yuv4_probe(AVProbeData *pd)
245 /* check file header */
246 if (strncmp(pd->buf, Y4M_MAGIC, sizeof(Y4M_MAGIC) - 1) == 0)
247 return AVPROBE_SCORE_MAX;
252 AVInputFormat ff_yuv4mpegpipe_demuxer = {
253 .name = "yuv4mpegpipe",
254 .long_name = NULL_IF_CONFIG_SMALL("YUV4MPEG pipe"),
255 .read_probe = yuv4_probe,
256 .read_header = yuv4_read_header,
257 .read_packet = yuv4_read_packet,