/* * Microsoft RLE video decoder * Copyright (C) 2003 the ffmpeg project * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * MS RLE video decoder by Mike Melanson (melanson@pcisys.net) * For more information about the MS RLE format, visit: * http://www.pcisys.net/~melanson/codecs/ * * The MS RLE decoder outputs PAL8 colorspace data. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include "avcodec.h" #include "internal.h" #include "msrledec.h" typedef struct MsrleContext { AVCodecContext *avctx; AVFrame *frame; GetByteContext gb; const unsigned char *buf; int size; uint32_t pal[256]; } MsrleContext; static av_cold int msrle_decode_init(AVCodecContext *avctx) { MsrleContext *s = avctx->priv_data; s->avctx = avctx; switch (avctx->bits_per_coded_sample) { case 4: case 8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break; case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break; default: av_log(avctx, AV_LOG_ERROR, "unsupported bits per sample\n"); return AVERROR_INVALIDDATA; } s->frame = av_frame_alloc(); if (!s->frame) return AVERROR(ENOMEM); return 0; } static int msrle_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; MsrleContext *s = avctx->priv_data; int istride = FFALIGN(avctx->width*avctx->bits_per_coded_sample, 32) / 8; int ret; s->buf = buf; s->size = buf_size; if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) { av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); return ret; } if (avctx->bits_per_coded_sample <= 8) { const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL); if (pal) { s->frame->palette_has_changed = 1; memcpy(s->pal, pal, AVPALETTE_SIZE); } /* make the palette available */ memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE); } /* FIXME how to correctly detect RLE ??? */ if (avctx->height * istride == avpkt->size) { /* assume uncompressed */ int linesize = avctx->width * avctx->bits_per_coded_sample / 8; uint8_t *ptr = s->frame->data[0]; uint8_t *buf = avpkt->data + (avctx->height-1)*istride; int i, j; for (i = 0; i < avctx->height; i++) { if (avctx->bits_per_coded_sample == 4) { for (j = 0; j < avctx->width - 1; j += 2) { ptr[j+0] = buf[j>>1] >> 4; ptr[j+1] = buf[j>>1] & 0xF; } if (avctx->width & 1) ptr[j+0] = buf[j>>1] >> 4; } else { memcpy(ptr, buf, linesize); } buf -= istride; ptr += s->frame->linesize[0]; } } else { bytestream2_init(&s->gb, buf, buf_size); ff_msrle_decode(avctx, (AVPicture*)s->frame, avctx->bits_per_coded_sample, &s->gb); } if ((ret = av_frame_ref(data, s->frame)) < 0) return ret; *got_frame = 1; /* report that the buffer was completely consumed */ return buf_size; } static av_cold int msrle_decode_end(AVCodecContext *avctx) { MsrleContext *s = avctx->priv_data; /* release the last frame */ av_frame_free(&s->frame); return 0; } AVCodec ff_msrle_decoder = { .name = "msrle", .long_name = NULL_IF_CONFIG_SMALL("Microsoft RLE"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_MSRLE, .priv_data_size = sizeof(MsrleContext), .init = msrle_decode_init, .close = msrle_decode_end, .decode = msrle_decode_frame, .capabilities = CODEC_CAP_DR1, };