static int g2m_decode_frame(AVCodecContext *avctx, void *data, int *got_picture_ptr, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; G2MContext *c = avctx->priv_data; AVFrame *pic = data; GetByteContext bc, tbc; int magic; int got_header = 0; uint32_t chunk_size, cur_size; int chunk_type; int i; int ret; if (buf_size < 12) { av_log(avctx, AV_LOG_ERROR, "Frame should have at least 12 bytes, got %d instead\n", buf_size); return AVERROR_INVALIDDATA; } bytestream2_init(&bc, buf, buf_size); magic = bytestream2_get_be32(&bc); if ((magic & ~0xF) != MKBETAG('G', '2', 'M', '0') || (magic & 0xF) < 2 || (magic & 0xF) > 4) { av_log(avctx, AV_LOG_ERROR, "Wrong magic %08X\n", magic); return AVERROR_INVALIDDATA; } if ((magic & 0xF) != 4) { av_log(avctx, AV_LOG_ERROR, "G2M2 and G2M3 are not yet supported\n"); return AVERROR(ENOSYS); } while (bytestream2_get_bytes_left(&bc) > 5) { chunk_size = bytestream2_get_le32(&bc) - 1; chunk_type = bytestream2_get_byte(&bc); if (chunk_size > bytestream2_get_bytes_left(&bc)) { av_log(avctx, AV_LOG_ERROR, "Invalid chunk size %d type %02X\n", chunk_size, chunk_type); break; } switch (chunk_type) { case FRAME_INFO: c->got_header = 0; if (chunk_size < 21) { av_log(avctx, AV_LOG_ERROR, "Invalid frame info size %d\n", chunk_size); break; } c->width = bytestream2_get_be32(&bc); c->height = bytestream2_get_be32(&bc); if (c->width < 16 || c->width > avctx->width || c->height < 16 || c->height > avctx->height) { av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d\n", c->width, c->height); c->width = c->height = 0; bytestream2_skip(&bc, bytestream2_get_bytes_left(&bc)); } if (c->width != avctx->width || c->height != avctx->height) avcodec_set_dimensions(avctx, c->width, c->height); c->compression = bytestream2_get_be32(&bc); if (c->compression != 2 && c->compression != 3) { av_log(avctx, AV_LOG_ERROR, "Unknown compression method %d\n", c->compression); return AVERROR_PATCHWELCOME; } c->tile_width = bytestream2_get_be32(&bc); c->tile_height = bytestream2_get_be32(&bc); if (!c->tile_width || !c->tile_height) { av_log(avctx, AV_LOG_ERROR, "Invalid tile dimensions %dx%d\n", c->tile_width, c->tile_height); return AVERROR_INVALIDDATA; } c->tiles_x = (c->width + c->tile_width - 1) / c->tile_width; c->tiles_y = (c->height + c->tile_height - 1) / c->tile_height; c->bpp = bytestream2_get_byte(&bc); chunk_size -= 21; bytestream2_skip(&bc, chunk_size); if (g2m_init_buffers(c)) return AVERROR(ENOMEM); got_header = 1; break; case TILE_DATA: if (!c->tiles_x || !c->tiles_y) { av_log(avctx, AV_LOG_WARNING, "No frame header - skipping tile\n"); bytestream2_skip(&bc, bytestream2_get_bytes_left(&bc)); break; } if (chunk_size < 2) { av_log(avctx, AV_LOG_ERROR, "Invalid tile data size %d\n", chunk_size); break; } c->tile_x = bytestream2_get_byte(&bc); c->tile_y = bytestream2_get_byte(&bc); if (c->tile_x >= c->tiles_x || c->tile_y >= c->tiles_y) { av_log(avctx, AV_LOG_ERROR, "Invalid tile pos %d,%d (in %dx%d grid)\n", c->tile_x, c->tile_y, c->tiles_x, c->tiles_y); break; } chunk_size -= 2; ret = 0; switch (c->compression) { case COMPR_EPIC_J_B: av_log(avctx, AV_LOG_ERROR, "ePIC j-b compression is not implemented yet\n"); return AVERROR(ENOSYS); case COMPR_KEMPF_J_B: ret = kempf_decode_tile(c, c->tile_x, c->tile_y, buf + bytestream2_tell(&bc), chunk_size); break; } if (ret && c->framebuf) av_log(avctx, AV_LOG_ERROR, "Error decoding tile %d,%d\n", c->tile_x, c->tile_y); bytestream2_skip(&bc, chunk_size); break; case CURSOR_POS: if (chunk_size < 5) { av_log(avctx, AV_LOG_ERROR, "Invalid cursor pos size %d\n", chunk_size); break; } c->cursor_x = bytestream2_get_be16(&bc); c->cursor_y = bytestream2_get_be16(&bc); bytestream2_skip(&bc, chunk_size - 4); break; case CURSOR_SHAPE: if (chunk_size < 8) { av_log(avctx, AV_LOG_ERROR, "Invalid cursor data size %d\n", chunk_size); break; } bytestream2_init(&tbc, buf + bytestream2_tell(&bc), chunk_size - 4); cur_size = bytestream2_get_be32(&tbc); c->cursor_w = bytestream2_get_byte(&tbc); c->cursor_h = bytestream2_get_byte(&tbc); c->cursor_hot_x = bytestream2_get_byte(&tbc); c->cursor_hot_y = bytestream2_get_byte(&tbc); c->cursor_fmt = bytestream2_get_byte(&tbc); if (cur_size >= chunk_size || c->cursor_w * c->cursor_h / 4 > cur_size) { av_log(avctx, AV_LOG_ERROR, "Invalid cursor data size %d\n", chunk_size); break; } g2m_load_cursor(c, &tbc); bytestream2_skip(&bc, chunk_size); break; case CHUNK_CC: case CHUNK_CD: bytestream2_skip(&bc, chunk_size); break; default: av_log(avctx, AV_LOG_WARNING, "Skipping chunk type %02X\n", chunk_type); bytestream2_skip(&bc, chunk_size); } } if (got_header) c->got_header = 1; if (c->width && c->height && c->framebuf) { if ((ret = ff_get_buffer(avctx, pic, 0)) < 0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return ret; } pic->key_frame = got_header; pic->pict_type = got_header ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P; for (i = 0; i < avctx->height; i++) memcpy(pic->data[0] + i * pic->linesize[0], c->framebuf + i * c->framebuf_stride, c->width * 3); g2m_paint_cursor(c, pic->data[0], pic->linesize[0]); *got_picture_ptr = 1; } return buf_size; }