static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { PicContext *s = avctx->priv_data; AVFrame *frame = data; uint32_t *palette; int bits_per_plane, bpp, etype, esize, npal, pos_after_pal; int i, x, y, plane, tmp, ret, val; bytestream2_init(&s->g, avpkt->data, avpkt->size); if (bytestream2_get_bytes_left(&s->g) < 11) return AVERROR_INVALIDDATA; if (bytestream2_get_le16u(&s->g) != 0x1234) return AVERROR_INVALIDDATA; s->width = bytestream2_get_le16u(&s->g); s->height = bytestream2_get_le16u(&s->g); bytestream2_skip(&s->g, 4); tmp = bytestream2_get_byteu(&s->g); bits_per_plane = tmp & 0xF; s->nb_planes = (tmp >> 4) + 1; bpp = bits_per_plane * s->nb_planes; if (bits_per_plane > 8 || bpp < 1 || bpp > 32) { avpriv_request_sample(avctx, "Unsupported bit depth"); return AVERROR_PATCHWELCOME; } if (bytestream2_peek_byte(&s->g) == 0xFF || bpp == 1 || bpp == 4 || bpp == 8) { bytestream2_skip(&s->g, 2); etype = bytestream2_get_le16(&s->g); esize = bytestream2_get_le16(&s->g); if (bytestream2_get_bytes_left(&s->g) < esize) return AVERROR_INVALIDDATA; } else { etype = -1; esize = 0; } avctx->pix_fmt = AV_PIX_FMT_PAL8; if (s->width != avctx->width && s->height != avctx->height) { if (av_image_check_size(s->width, s->height, 0, avctx) < 0) return -1; avcodec_set_dimensions(avctx, s->width, s->height); } if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) return ret; memset(frame->data[0], 0, s->height * frame->linesize[0]); frame->pict_type = AV_PICTURE_TYPE_I; frame->palette_has_changed = 1; pos_after_pal = bytestream2_tell(&s->g) + esize; palette = (uint32_t*)frame->data[1]; if (etype == 1 && esize > 1 && bytestream2_peek_byte(&s->g) < 6) { int idx = bytestream2_get_byte(&s->g); npal = 4; for (i = 0; i < npal; i++) palette[i] = ff_cga_palette[ cga_mode45_index[idx][i] ]; } else if (etype == 2) { npal = FFMIN(esize, 16); for (i = 0; i < npal; i++) { int pal_idx = bytestream2_get_byte(&s->g); palette[i] = ff_cga_palette[FFMIN(pal_idx, 15)]; } } else if (etype == 3) { npal = FFMIN(esize, 16); for (i = 0; i < npal; i++) { int pal_idx = bytestream2_get_byte(&s->g); palette[i] = ff_ega_palette[FFMIN(pal_idx, 63)]; } } else if (etype == 4 || etype == 5) { npal = FFMIN(esize / 3, 256); for (i = 0; i < npal; i++) { palette[i] = bytestream2_get_be24(&s->g) << 2; palette[i] |= 0xFFU << 24 | palette[i] >> 6 & 0x30303; } } else { if (bpp == 1) { npal = 2; palette[0] = 0xFF000000; palette[1] = 0xFFFFFFFF; } else if (bpp == 2) { npal = 4; for (i = 0; i < npal; i++) palette[i] = ff_cga_palette[ cga_mode45_index[0][i] ]; } else { npal = 16; memcpy(palette, ff_cga_palette, npal * 4); } } // fill remaining palette entries memset(palette + npal, 0, AVPALETTE_SIZE - npal * 4); // skip remaining palette bytes bytestream2_seek(&s->g, pos_after_pal, SEEK_SET); val = 0; y = s->height - 1; if (bytestream2_get_le16(&s->g)) { x = 0; plane = 0; while (y >= 0 && bytestream2_get_bytes_left(&s->g) >= 6) { int stop_size, marker, t1, t2; t1 = bytestream2_get_bytes_left(&s->g); t2 = bytestream2_get_le16(&s->g); stop_size = t1 - FFMIN(t1, t2); // ignore uncompressed block size bytestream2_skip(&s->g, 2); marker = bytestream2_get_byte(&s->g); while (plane < s->nb_planes && y >= 0 && bytestream2_get_bytes_left(&s->g) > stop_size) { int run = 1; val = bytestream2_get_byte(&s->g); if (val == marker) { run = bytestream2_get_byte(&s->g); if (run == 0) run = bytestream2_get_le16(&s->g); val = bytestream2_get_byte(&s->g); } if (!bytestream2_get_bytes_left(&s->g)) break; if (bits_per_plane == 8) { picmemset_8bpp(s, frame, val, run, &x, &y); if (y < 0) goto finish; } else { picmemset(s, frame, val, run, &x, &y, &plane, bits_per_plane); } } } if (x < avctx->width && y >= 0) { int run = (y + 1) * avctx->width - x; if (bits_per_plane == 8) picmemset_8bpp(s, frame, val, run, &x, &y); else picmemset(s, frame, val, run / (8 / bits_per_plane), &x, &y, &plane, bits_per_plane); } } else { while (y >= 0 && bytestream2_get_bytes_left(&s->g) > 0) { memcpy(frame->data[0] + y * frame->linesize[0], s->g.buffer, FFMIN(avctx->width, bytestream2_get_bytes_left(&s->g))); bytestream2_skip(&s->g, avctx->width); y--; } } finish: *got_frame = 1; return avpkt->size; }