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-rw-r--r--libavcodec/cpia.c218
1 files changed, 218 insertions, 0 deletions
diff --git a/libavcodec/cpia.c b/libavcodec/cpia.c
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+++ b/libavcodec/cpia.c
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+/*
+ * CPiA video decoder.
+ * Copyright (c) 2010 Hans de Goede <hdegoede@redhat.com>
+ *
+ * This decoder is based on the LGPL code available at
+ * https://v4l4j.googlecode.com/svn/v4l4j/trunk/libvideo/libv4lconvert/cpia1.c
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "avcodec.h"
+#include "get_bits.h"
+
+
+#define FRAME_HEADER_SIZE 64
+#define MAGIC_0 0x19 /**< First header byte */
+#define MAGIC_1 0x68 /**< Second header byte */
+#define SUBSAMPLE_420 0
+#define SUBSAMPLE_422 1
+#define YUVORDER_YUYV 0
+#define YUVORDER_UYVY 1
+#define NOT_COMPRESSED 0
+#define COMPRESSED 1
+#define NO_DECIMATION 0
+#define DECIMATION_ENAB 1
+#define EOL 0xfd /**< End Of Line marker */
+#define EOI 0xff /**< End Of Image marker */
+
+
+typedef struct {
+ AVFrame frame;
+} CpiaContext;
+
+
+static int cpia_decode_frame(AVCodecContext *avctx,
+ void *data, int *got_frame, AVPacket* avpkt)
+{
+ CpiaContext* const cpia = avctx->priv_data;
+ int i,j,ret;
+
+ uint8_t* const header = avpkt->data;
+ uint8_t* src;
+ int src_size;
+ uint16_t linelength;
+ uint8_t skip;
+
+ AVFrame* const frame = &cpia->frame;
+ uint8_t *y, *u, *v, *y_end, *u_end, *v_end;
+
+ // Check header
+ if ( avpkt->size < FRAME_HEADER_SIZE
+ || header[0] != MAGIC_0 || header[1] != MAGIC_1
+ || (header[17] != SUBSAMPLE_420 && header[17] != SUBSAMPLE_422)
+ || (header[18] != YUVORDER_YUYV && header[18] != YUVORDER_UYVY)
+ || (header[28] != NOT_COMPRESSED && header[28] != COMPRESSED)
+ || (header[29] != NO_DECIMATION && header[29] != DECIMATION_ENAB)
+ ) {
+ av_log(avctx, AV_LOG_ERROR, "Invalid header!\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ // currently unsupported properties
+ if (header[17] == SUBSAMPLE_422) {
+ av_log(avctx, AV_LOG_ERROR, "Unsupported subsample!\n");
+ return AVERROR_PATCHWELCOME;
+ }
+ if (header[18] == YUVORDER_UYVY) {
+ av_log(avctx, AV_LOG_ERROR, "Unsupported YUV byte order!\n");
+ return AVERROR_PATCHWELCOME;
+ }
+ if (header[29] == DECIMATION_ENAB) {
+ av_log(avctx, AV_LOG_ERROR, "Decimation unsupported!\n");
+ return AVERROR_PATCHWELCOME;
+ }
+
+ src = header + FRAME_HEADER_SIZE;
+ src_size = avpkt->size - FRAME_HEADER_SIZE;
+
+ if (header[28] == NOT_COMPRESSED) {
+ frame->pict_type = AV_PICTURE_TYPE_I;
+ frame->key_frame = 1;
+ } else {
+ frame->pict_type = AV_PICTURE_TYPE_P;
+ frame->key_frame = 0;
+ }
+
+ // Get buffer filled with previous frame
+ if ((ret = avctx->reget_buffer(avctx, frame)) < 0) {
+ av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed!\n");
+ return ret;
+ }
+
+
+ for ( i = 0;
+ i < frame->height;
+ i++, src += linelength, src_size -= linelength
+ ) {
+ // Read line length, two byte little endian
+ linelength = AV_RL16(src);
+ src += 2;
+
+ if (src_size < linelength) {
+ frame->decode_error_flags = FF_DECODE_ERROR_INVALID_BITSTREAM;
+ av_log(avctx, AV_LOG_WARNING, "Frame ended enexpectedly!\n");
+ break;
+ }
+ if (src[linelength - 1] != EOL) {
+ frame->decode_error_flags = FF_DECODE_ERROR_INVALID_BITSTREAM;
+ av_log(avctx, AV_LOG_WARNING, "Wrong line length %d or line not terminated properly (found 0x%02x)!\n", linelength, src[linelength - 1]);
+ break;
+ }
+
+ /* Update the data pointers. Y data is on every line.
+ * U and V data on every second line
+ */
+ y = &frame->data[0][i * frame->linesize[0]];
+ u = &frame->data[1][(i >> 1) * frame->linesize[1]];
+ v = &frame->data[2][(i >> 1) * frame->linesize[2]];
+ y_end = y + frame->linesize[0] - 1;
+ u_end = u + frame->linesize[1] - 1;
+ v_end = v + frame->linesize[2] - 1;
+
+ if ((i & 1) && header[17] == SUBSAMPLE_420) {
+ /* We are on a odd line and 420 subsample is used.
+ * On this line only Y values are specified, one per pixel.
+ */
+ for (j = 0; j < linelength - 1; j++) {
+ if (y > y_end) {
+ frame->decode_error_flags = FF_DECODE_ERROR_INVALID_BITSTREAM;
+ av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n");
+ break;
+ }
+ if ((src[j] & 1) && header[28] == COMPRESSED) {
+ /* It seems that odd lines are always uncompressed, but
+ * we do it according to specification anyways.
+ */
+ skip = src[j] >> 1;
+ y += skip;
+ } else {
+ *(y++) = src[j];
+ }
+ }
+ } else if (header[17] == SUBSAMPLE_420) {
+ /* We are on an even line and 420 subsample is used.
+ * On this line each pair of pixels is described by four bytes.
+ */
+ for (j = 0; j < linelength - 4; ) {
+ if (y + 1 > y_end || u > u_end || v > v_end) {
+ frame->decode_error_flags = FF_DECODE_ERROR_INVALID_BITSTREAM;
+ av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n");
+ break;
+ }
+ if ((src[j] & 1) && header[28] == COMPRESSED) {
+ // Skip amount of pixels and move forward one byte
+ skip = src[j] >> 1;
+ y += skip;
+ u += skip >> 1;
+ v += skip >> 1;
+ j++;
+ } else {
+ // Set image data as specified and move forward 4 bytes
+ *(y++) = src[j];
+ *(u++) = src[j+1];
+ *(y++) = src[j+2];
+ *(v++) = src[j+3];
+ j += 4;
+ }
+ }
+ }
+ }
+
+ *got_frame = 1;
+ *(AVFrame*) data = *frame;
+
+ return avpkt->size;
+}
+
+static av_cold int cpia_decode_init(AVCodecContext *avctx)
+{
+ // output pixel format
+ avctx->pix_fmt = AV_PIX_FMT_YUV420P;
+
+ /* The default timebase set by the v4l2 demuxer leads to probing which is buggy.
+ * Set some reasonable time_base to skip this.
+ */
+ if (avctx->time_base.num == 1 && avctx->time_base.den == 1000000) {
+ avctx->time_base.num = 1;
+ avctx->time_base.den = 60;
+ }
+
+ return 0;
+}
+
+
+AVCodec ff_cpia_decoder = {
+ .name = "cpia",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .id = AV_CODEC_ID_CPIA,
+ .priv_data_size = sizeof(CpiaContext),
+ .init = cpia_decode_init,
+ .decode = cpia_decode_frame,
+ .capabilities = CODEC_CAP_DR1,
+ .long_name = NULL_IF_CONFIG_SMALL("CPiA video format"),
+};
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