2 * DPX (.dpx) image decoder
3 * Copyright (c) 2009 Jimmy Christensen
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
22 #include "libavutil/intreadwrite.h"
23 #include "libavutil/imgutils.h"
24 #include "bytestream.h"
27 typedef struct DPXContext {
32 static unsigned int read32(const uint8_t **ptr, int is_big)
44 static inline unsigned make_16bit(unsigned value)
46 // mask away invalid bits
48 // correctly expand to 16 bits
49 return value + (value >> 10);
52 static int decode_frame(AVCodecContext *avctx,
57 const uint8_t *buf = avpkt->data;
58 const uint8_t *buf_end = avpkt->data + avpkt->size;
59 int buf_size = avpkt->size;
60 DPXContext *const s = avctx->priv_data;
61 AVFrame *picture = data;
62 AVFrame *const p = &s->picture;
66 int magic_num, endian;
68 int w, h, stride, bits_per_color, descriptor, elements, target_packet_size, source_packet_size;
70 unsigned int rgbBuffer;
72 if (avpkt->size <= 1634) {
73 av_log(avctx, AV_LOG_ERROR, "Packet too small for DPX header\n");
74 return AVERROR_INVALIDDATA;
77 magic_num = AV_RB32(buf);
80 /* Check if the files "magic number" is "SDPX" which means it uses
81 * big-endian or XPDS which is for little-endian files */
82 if (magic_num == AV_RL32("SDPX")) {
84 } else if (magic_num == AV_RB32("SDPX")) {
87 av_log(avctx, AV_LOG_ERROR, "DPX marker not found\n");
91 offset = read32(&buf, endian);
92 if (avpkt->size <= offset) {
93 av_log(avctx, AV_LOG_ERROR, "Invalid data start offset\n");
94 return AVERROR_INVALIDDATA;
96 // Need to end in 0x304 offset from start of file
97 buf = avpkt->data + 0x304;
98 w = read32(&buf, endian);
99 h = read32(&buf, endian);
101 // Need to end in 0x320 to read the descriptor
105 // Need to end in 0x323 to read the bits per color
107 avctx->bits_per_raw_sample =
108 bits_per_color = buf[0];
111 avctx->sample_aspect_ratio.num = read32(&buf, endian);
112 avctx->sample_aspect_ratio.den = read32(&buf, endian);
114 switch (descriptor) {
122 av_log(avctx, AV_LOG_ERROR, "Unsupported descriptor %d\n", descriptor);
126 switch (bits_per_color) {
129 avctx->pix_fmt = PIX_FMT_RGBA;
131 avctx->pix_fmt = PIX_FMT_RGB24;
133 source_packet_size = elements;
134 target_packet_size = elements;
137 avctx->pix_fmt = PIX_FMT_RGB48;
138 target_packet_size = 6;
139 source_packet_size = 4;
144 avctx->pix_fmt = PIX_FMT_RGB48BE;
146 avctx->pix_fmt = PIX_FMT_RGB48LE;
148 target_packet_size = 6;
149 source_packet_size = elements * 2;
152 av_log(avctx, AV_LOG_ERROR, "Unsupported color depth : %d\n", bits_per_color);
156 if (s->picture.data[0])
157 avctx->release_buffer(avctx, &s->picture);
158 if (av_image_check_size(w, h, 0, avctx))
160 if (w != avctx->width || h != avctx->height)
161 avcodec_set_dimensions(avctx, w, h);
162 if (avctx->get_buffer(avctx, p) < 0) {
163 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
167 // Move pointer to offset from start of file
168 buf = avpkt->data + offset;
171 stride = p->linesize[0];
173 if (source_packet_size*avctx->width*avctx->height > buf_end - buf) {
174 av_log(avctx, AV_LOG_ERROR, "Overread buffer. Invalid header?\n");
177 switch (bits_per_color) {
179 for (x = 0; x < avctx->height; x++) {
180 uint16_t *dst = (uint16_t*)ptr;
181 for (y = 0; y < avctx->width; y++) {
182 rgbBuffer = read32(&buf, endian);
183 // Read out the 10-bit colors and convert to 16-bit
184 *dst++ = make_16bit(rgbBuffer >> 16);
185 *dst++ = make_16bit(rgbBuffer >> 6);
186 *dst++ = make_16bit(rgbBuffer << 4);
192 case 12: // Treat 12-bit as 16-bit
194 if (source_packet_size == target_packet_size) {
195 for (x = 0; x < avctx->height; x++) {
196 memcpy(ptr, buf, target_packet_size*avctx->width);
198 buf += source_packet_size*avctx->width;
201 for (x = 0; x < avctx->height; x++) {
203 for (y = 0; y < avctx->width; y++) {
204 memcpy(dst, buf, target_packet_size);
205 dst += target_packet_size;
206 buf += source_packet_size;
214 *picture = s->picture;
215 *data_size = sizeof(AVPicture);
220 static av_cold int decode_init(AVCodecContext *avctx)
222 DPXContext *s = avctx->priv_data;
223 avcodec_get_frame_defaults(&s->picture);
224 avctx->coded_frame = &s->picture;
228 static av_cold int decode_end(AVCodecContext *avctx)
230 DPXContext *s = avctx->priv_data;
231 if (s->picture.data[0])
232 avctx->release_buffer(avctx, &s->picture);
237 AVCodec ff_dpx_decoder = {
239 .type = AVMEDIA_TYPE_VIDEO,
240 .id = AV_CODEC_ID_DPX,
241 .priv_data_size = sizeof(DPXContext),
244 .decode = decode_frame,
245 .long_name = NULL_IF_CONFIG_SMALL("DPX image"),