/* * 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 "libavutil/intreadwrite.h"#include "avcodec.h"#include "codec_internal.h"#include "decode.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, AVFrame *rframe,                             int *got_frame, AVPacket* avpkt){    CpiaContext* const cpia = avctx->priv_data;    int i,j,ret;     const uint8_t *const header = avpkt->data;    const uint8_t *src;    int src_size;    uint16_t linelength;    uint8_t skip;     AVFrame *frame = cpia->frame;    uint8_t *y, *u, *v, *y_end, *u_end, *v_end;     // Check header    if ( avpkt->size < FRAME_HEADER_SIZE + avctx->height * 3      || 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) {        avpriv_report_missing_feature(avctx, "4:2:2 subsampling");        return AVERROR_PATCHWELCOME;    }    if (header[18] == YUVORDER_UYVY) {        avpriv_report_missing_feature(avctx, "YUV byte order UYVY");        return AVERROR_PATCHWELCOME;    }    if (header[29] == DECIMATION_ENAB) {        avpriv_report_missing_feature(avctx, "Decimation");        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->flags |= AV_FRAME_FLAG_KEY;    } else {        frame->pict_type = AV_PICTURE_TYPE_P;        frame->flags &= ~AV_FRAME_FLAG_KEY;    }     // Get buffer filled with previous frame    if ((ret = ff_reget_buffer(avctx, frame, 0)) < 0)        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;        src_size -= 2;         if (src_size < linelength) {            frame->decode_error_flags = FF_DECODE_ERROR_INVALID_BITSTREAM;            av_log(avctx, AV_LOG_WARNING, "Frame ended unexpectedly!\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 an 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;    if ((ret = av_frame_ref(rframe, cpia->frame)) < 0)        return ret;     return avpkt->size;} static av_cold int cpia_decode_init(AVCodecContext *avctx){    CpiaContext *s = avctx->priv_data;     // output pixel format    avctx->pix_fmt = AV_PIX_FMT_YUV420P;     s->frame = av_frame_alloc();    if (!s->frame)        return AVERROR(ENOMEM);     return 0;} static av_cold int cpia_decode_end(AVCodecContext *avctx){    CpiaContext *s = avctx->priv_data;     av_frame_free(&s->frame);     return 0;} const FFCodec ff_cpia_decoder = {    .p.name         = "cpia",    CODEC_LONG_NAME("CPiA video format"),    .p.type         = AVMEDIA_TYPE_VIDEO,    .p.id           = AV_CODEC_ID_CPIA,    .priv_data_size = sizeof(CpiaContext),    .init           = cpia_decode_init,    .close          = cpia_decode_end,    FF_CODEC_DECODE_CB(cpia_decode_frame),    .p.capabilities = AV_CODEC_CAP_DR1,};