yading@10: /*
yading@10:  * QPEG codec
yading@10:  * Copyright (c) 2004 Konstantin Shishkov
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * QPEG codec.
yading@10:  */
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #include "bytestream.h"
yading@10: #include "internal.h"
yading@10: 
yading@10: typedef struct QpegContext{
yading@10:     AVCodecContext *avctx;
yading@10:     AVFrame pic, ref;
yading@10:     uint32_t pal[256];
yading@10:     GetByteContext buffer;
yading@10: } QpegContext;
yading@10: 
yading@10: static void qpeg_decode_intra(QpegContext *qctx, uint8_t *dst,
yading@10:                               int stride, int width, int height)
yading@10: {
yading@10:     int i;
yading@10:     int code;
yading@10:     int c0, c1;
yading@10:     int run, copy;
yading@10:     int filled = 0;
yading@10:     int rows_to_go;
yading@10: 
yading@10:     rows_to_go = height;
yading@10:     height--;
yading@10:     dst = dst + height * stride;
yading@10: 
yading@10:     while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (rows_to_go > 0)) {
yading@10:         code = bytestream2_get_byte(&qctx->buffer);
yading@10:         run = copy = 0;
yading@10:         if(code == 0xFC) /* end-of-picture code */
yading@10:             break;
yading@10:         if(code >= 0xF8) { /* very long run */
yading@10:             c0 = bytestream2_get_byte(&qctx->buffer);
yading@10:             c1 = bytestream2_get_byte(&qctx->buffer);
yading@10:             run = ((code & 0x7) << 16) + (c0 << 8) + c1 + 2;
yading@10:         } else if (code >= 0xF0) { /* long run */
yading@10:             c0 = bytestream2_get_byte(&qctx->buffer);
yading@10:             run = ((code & 0xF) << 8) + c0 + 2;
yading@10:         } else if (code >= 0xE0) { /* short run */
yading@10:             run = (code & 0x1F) + 2;
yading@10:         } else if (code >= 0xC0) { /* very long copy */
yading@10:             c0 = bytestream2_get_byte(&qctx->buffer);
yading@10:             c1 = bytestream2_get_byte(&qctx->buffer);
yading@10:             copy = ((code & 0x3F) << 16) + (c0 << 8) + c1 + 1;
yading@10:         } else if (code >= 0x80) { /* long copy */
yading@10:             c0 = bytestream2_get_byte(&qctx->buffer);
yading@10:             copy = ((code & 0x7F) << 8) + c0 + 1;
yading@10:         } else { /* short copy */
yading@10:             copy = code + 1;
yading@10:         }
yading@10: 
yading@10:         /* perform actual run or copy */
yading@10:         if(run) {
yading@10:             int p;
yading@10: 
yading@10:             p = bytestream2_get_byte(&qctx->buffer);
yading@10:             for(i = 0; i < run; i++) {
yading@10:                 dst[filled++] = p;
yading@10:                 if (filled >= width) {
yading@10:                     filled = 0;
yading@10:                     dst -= stride;
yading@10:                     rows_to_go--;
yading@10:                     if(rows_to_go <= 0)
yading@10:                         break;
yading@10:                 }
yading@10:             }
yading@10:         } else {
yading@10:             for(i = 0; i < copy; i++) {
yading@10:                 dst[filled++] = bytestream2_get_byte(&qctx->buffer);
yading@10:                 if (filled >= width) {
yading@10:                     filled = 0;
yading@10:                     dst -= stride;
yading@10:                     rows_to_go--;
yading@10:                     if(rows_to_go <= 0)
yading@10:                         break;
yading@10:                 }
yading@10:             }
yading@10:         }
yading@10:     }
yading@10: }
yading@10: 
yading@10: static const int qpeg_table_h[16] =
yading@10:  { 0x00, 0x20, 0x20, 0x20, 0x18, 0x10, 0x10, 0x20, 0x10, 0x08, 0x18, 0x08, 0x08, 0x18, 0x10, 0x04};
yading@10: static const int qpeg_table_w[16] =
yading@10:  { 0x00, 0x20, 0x18, 0x08, 0x18, 0x10, 0x20, 0x10, 0x08, 0x10, 0x20, 0x20, 0x08, 0x10, 0x18, 0x04};
yading@10: 
yading@10: /* Decodes delta frames */
yading@10: static void qpeg_decode_inter(QpegContext *qctx, uint8_t *dst,
yading@10:                               int stride, int width, int height,
yading@10:                               int delta, const uint8_t *ctable,
yading@10:                               uint8_t *refdata)
yading@10: {
yading@10:     int i, j;
yading@10:     int code;
yading@10:     int filled = 0;
yading@10:     int orig_height;
yading@10: 
yading@10:     if(!refdata)
yading@10:         refdata= dst;
yading@10: 
yading@10:     /* copy prev frame */
yading@10:     for(i = 0; i < height; i++)
yading@10:         memcpy(dst + (i * stride), refdata + (i * stride), width);
yading@10: 
yading@10:     orig_height = height;
yading@10:     height--;
yading@10:     dst = dst + height * stride;
yading@10: 
yading@10:     while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (height >= 0)) {
yading@10:         code = bytestream2_get_byte(&qctx->buffer);
yading@10: 
yading@10:         if(delta) {
yading@10:             /* motion compensation */
yading@10:             while(bytestream2_get_bytes_left(&qctx->buffer) > 0 && (code & 0xF0) == 0xF0) {
yading@10:                 if(delta == 1) {
yading@10:                     int me_idx;
yading@10:                     int me_w, me_h, me_x, me_y;
yading@10:                     uint8_t *me_plane;
yading@10:                     int corr, val;
yading@10: 
yading@10:                     /* get block size by index */
yading@10:                     me_idx = code & 0xF;
yading@10:                     me_w = qpeg_table_w[me_idx];
yading@10:                     me_h = qpeg_table_h[me_idx];
yading@10: 
yading@10:                     /* extract motion vector */
yading@10:                     corr = bytestream2_get_byte(&qctx->buffer);
yading@10: 
yading@10:                     val = corr >> 4;
yading@10:                     if(val > 7)
yading@10:                         val -= 16;
yading@10:                     me_x = val;
yading@10: 
yading@10:                     val = corr & 0xF;
yading@10:                     if(val > 7)
yading@10:                         val -= 16;
yading@10:                     me_y = val;
yading@10: 
yading@10:                     /* check motion vector */
yading@10:                     if ((me_x + filled < 0) || (me_x + me_w + filled > width) ||
yading@10:                        (height - me_y - me_h < 0) || (height - me_y > orig_height) ||
yading@10:                        (filled + me_w > width) || (height - me_h < 0))
yading@10:                         av_log(NULL, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n",
yading@10:                                me_x, me_y, me_w, me_h, filled, height);
yading@10:                     else {
yading@10:                         /* do motion compensation */
yading@10:                         me_plane = refdata + (filled + me_x) + (height - me_y) * stride;
yading@10:                         for(j = 0; j < me_h; j++) {
yading@10:                             for(i = 0; i < me_w; i++)
yading@10:                                 dst[filled + i - (j * stride)] = me_plane[i - (j * stride)];
yading@10:                         }
yading@10:                     }
yading@10:                 }
yading@10:                 code = bytestream2_get_byte(&qctx->buffer);
yading@10:             }
yading@10:         }
yading@10: 
yading@10:         if(code == 0xE0) /* end-of-picture code */
yading@10:             break;
yading@10:         if(code > 0xE0) { /* run code: 0xE1..0xFF */
yading@10:             int p;
yading@10: 
yading@10:             code &= 0x1F;
yading@10:             p = bytestream2_get_byte(&qctx->buffer);
yading@10:             for(i = 0; i <= code; i++) {
yading@10:                 dst[filled++] = p;
yading@10:                 if(filled >= width) {
yading@10:                     filled = 0;
yading@10:                     dst -= stride;
yading@10:                     height--;
yading@10:                     if(height < 0)
yading@10:                         break;
yading@10:                 }
yading@10:             }
yading@10:         } else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */
yading@10:             code &= 0x1F;
yading@10: 
yading@10:             if(code + 1 > bytestream2_get_bytes_left(&qctx->buffer))
yading@10:                 break;
yading@10: 
yading@10:             for(i = 0; i <= code; i++) {
yading@10:                 dst[filled++] = bytestream2_get_byte(&qctx->buffer);
yading@10:                 if(filled >= width) {
yading@10:                     filled = 0;
yading@10:                     dst -= stride;
yading@10:                     height--;
yading@10:                     if(height < 0)
yading@10:                         break;
yading@10:                 }
yading@10:             }
yading@10:         } else if(code >= 0x80) { /* skip code: 0x80..0xBF */
yading@10:             int skip;
yading@10: 
yading@10:             code &= 0x3F;
yading@10:             /* codes 0x80 and 0x81 are actually escape codes,
yading@10:                skip value minus constant is in the next byte */
yading@10:             if(!code)
yading@10:                 skip = bytestream2_get_byte(&qctx->buffer) +  64;
yading@10:             else if(code == 1)
yading@10:                 skip = bytestream2_get_byte(&qctx->buffer) + 320;
yading@10:             else
yading@10:                 skip = code;
yading@10:             filled += skip;
yading@10:             while( filled >= width) {
yading@10:                 filled -= width;
yading@10:                 dst -= stride;
yading@10:                 height--;
yading@10:                 if(height < 0)
yading@10:                     break;
yading@10:             }
yading@10:         } else {
yading@10:             /* zero code treated as one-pixel skip */
yading@10:             if(code) {
yading@10:                 dst[filled++] = ctable[code & 0x7F];
yading@10:             }
yading@10:             else
yading@10:                 filled++;
yading@10:             if(filled >= width) {
yading@10:                 filled = 0;
yading@10:                 dst -= stride;
yading@10:                 height--;
yading@10:             }
yading@10:         }
yading@10:     }
yading@10: }
yading@10: 
yading@10: static int decode_frame(AVCodecContext *avctx,
yading@10:                         void *data, int *got_frame,
yading@10:                         AVPacket *avpkt)
yading@10: {
yading@10:     uint8_t ctable[128];
yading@10:     QpegContext * const a = avctx->priv_data;
yading@10:     AVFrame *  p = &a->pic;
yading@10:     AVFrame * ref= &a->ref;
yading@10:     uint8_t* outdata;
yading@10:     int delta, ret;
yading@10:     const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
yading@10: 
yading@10:     if (avpkt->size < 0x86) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     bytestream2_init(&a->buffer, avpkt->data, avpkt->size);
yading@10: 
yading@10:     av_frame_unref(ref);
yading@10:     av_frame_move_ref(ref, p);
yading@10: 
yading@10:     if ((ret = ff_get_buffer(avctx, p, AV_GET_BUFFER_FLAG_REF)) < 0)
yading@10:         return ret;
yading@10:     outdata = a->pic.data[0];
yading@10:     bytestream2_skip(&a->buffer, 4);
yading@10:     bytestream2_get_buffer(&a->buffer, ctable, 128);
yading@10:     bytestream2_skip(&a->buffer, 1);
yading@10: 
yading@10:     delta = bytestream2_get_byte(&a->buffer);
yading@10:     if(delta == 0x10) {
yading@10:         qpeg_decode_intra(a, outdata, a->pic.linesize[0], avctx->width, avctx->height);
yading@10:     } else {
yading@10:         qpeg_decode_inter(a, outdata, a->pic.linesize[0], avctx->width, avctx->height, delta, ctable, a->ref.data[0]);
yading@10:     }
yading@10: 
yading@10:     /* make the palette available on the way out */
yading@10:     if (pal) {
yading@10:         a->pic.palette_has_changed = 1;
yading@10:         memcpy(a->pal, pal, AVPALETTE_SIZE);
yading@10:     }
yading@10:     memcpy(a->pic.data[1], a->pal, AVPALETTE_SIZE);
yading@10: 
yading@10:     if ((ret = av_frame_ref(data, &a->pic)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     *got_frame      = 1;
yading@10: 
yading@10:     return avpkt->size;
yading@10: }
yading@10: 
yading@10: static void decode_flush(AVCodecContext *avctx){
yading@10:     QpegContext * const a = avctx->priv_data;
yading@10:     int i, pal_size;
yading@10:     const uint8_t *pal_src;
yading@10: 
yading@10:     pal_size = FFMIN(1024U, avctx->extradata_size);
yading@10:     pal_src = avctx->extradata + avctx->extradata_size - pal_size;
yading@10: 
yading@10:     for (i=0; i<pal_size/4; i++)
yading@10:         a->pal[i] = 0xFFU<<24 | AV_RL32(pal_src+4*i);
yading@10: }
yading@10: 
yading@10: static av_cold int decode_init(AVCodecContext *avctx){
yading@10:     QpegContext * const a = avctx->priv_data;
yading@10: 
yading@10:     avcodec_get_frame_defaults(&a->pic);
yading@10:     avcodec_get_frame_defaults(&a->ref);
yading@10:     a->avctx = avctx;
yading@10:     avctx->pix_fmt= AV_PIX_FMT_PAL8;
yading@10: 
yading@10:     decode_flush(avctx);
yading@10: 
yading@10:     avcodec_get_frame_defaults(&a->pic);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static av_cold int decode_end(AVCodecContext *avctx){
yading@10:     QpegContext * const a = avctx->priv_data;
yading@10:     AVFrame * const p = &a->pic;
yading@10:     AVFrame * const ref= &a->ref;
yading@10: 
yading@10:     av_frame_unref(p);
yading@10:     av_frame_unref(ref);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: AVCodec ff_qpeg_decoder = {
yading@10:     .name           = "qpeg",
yading@10:     .type           = AVMEDIA_TYPE_VIDEO,
yading@10:     .id             = AV_CODEC_ID_QPEG,
yading@10:     .priv_data_size = sizeof(QpegContext),
yading@10:     .init           = decode_init,
yading@10:     .close          = decode_end,
yading@10:     .decode         = decode_frame,
yading@10:     .flush          = decode_flush,
yading@10:     .capabilities   = CODEC_CAP_DR1,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("Q-team QPEG"),
yading@10: };