- AVIOContext *pb;
- int64_t crc_offset;
- int ret, size;
- uint8_t *buf;
-
- ret = avio_open_dyn_buf(&pb);
- if (ret < 0)
- return ret;
- ffio_init_checksum(pb, ff_crc04C11DB7_update, 0);
- ffio_wfourcc(pb, "OggS");
- avio_w8(pb, 0);
- avio_w8(pb, page->flags | extra_flags);
- avio_wl64(pb, page->granule);
- avio_wl32(pb, oggstream->serial_num);
- avio_wl32(pb, oggstream->page_counter++);
- crc_offset = avio_tell(pb);
- avio_wl32(pb, 0); // crc
- avio_w8(pb, page->segments_count);
- avio_write(pb, page->segments, page->segments_count);
- avio_write(pb, page->data, page->size);
-
- ogg_update_checksum(s, pb, crc_offset);
- avio_flush(pb);
-
- size = avio_close_dyn_buf(pb, &buf);
- if (size < 0)
- return size;
-
- avio_write(s->pb, buf, size);
- avio_flush(s->pb);
- av_free(buf);
+ uint8_t buf[4 + 1 + 1 + 8 + 4 + 4 + 4 + 1 + 255], *ptr = buf, *crc_pos;
+ const AVCRC *crc_table = av_crc_get_table(AV_CRC_32_IEEE);
+ uint32_t crc;
+
+ bytestream_put_le32(&ptr, MKTAG('O', 'g', 'g', 'S'));
+ bytestream_put_byte(&ptr, 0);
+ bytestream_put_byte(&ptr, page->flags | extra_flags);
+ bytestream_put_le64(&ptr, page->granule);
+ bytestream_put_le32(&ptr, oggstream->serial_num);
+ bytestream_put_le32(&ptr, oggstream->page_counter++);
+ crc_pos = ptr;
+ bytestream_put_le32(&ptr, 0);
+ bytestream_put_byte(&ptr, page->segments_count);
+ bytestream_put_buffer(&ptr, page->segments, page->segments_count);
+
+ crc = av_crc(crc_table, 0, buf, ptr - buf);
+ crc = av_crc(crc_table, crc, page->data, page->size);
+ bytestream_put_be32(&crc_pos, crc);
+
+ avio_write(s->pb, buf, ptr - buf);
+ avio_write(s->pb, page->data, page->size);
+ avio_write_marker(s->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_FLUSH_POINT);