diff options
Diffstat (limited to 'libavcodec/truehd_core_bsf.c')
| -rw-r--r-- | libavcodec/truehd_core_bsf.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/libavcodec/truehd_core_bsf.c b/libavcodec/truehd_core_bsf.c new file mode 100644 index 0000000000..be021af8e8 --- /dev/null +++ b/libavcodec/truehd_core_bsf.c @@ -0,0 +1,184 @@ +/* + * Copyright (c) 2018 Paul B Mahol + * + * This file is part of FFmpeg. + * + * FFmpeg 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. + * + * FFmpeg 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 FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "avcodec.h" +#include "bsf.h" +#include "get_bits.h" +#include "mlp_parser.h" +#include "mlp.h" + +typedef struct AccessUnit { + uint8_t bits[4]; + uint16_t offset; + uint16_t optional; +} AccessUnit; + +typedef struct TrueHDCoreContext { + const AVClass *class; + + MLPHeaderInfo hdr; +} TrueHDCoreContext; + +static int truehd_core_filter(AVBSFContext *ctx, AVPacket *out) +{ + TrueHDCoreContext *s = ctx->priv_data; + GetBitContext gbc; + AccessUnit units[MAX_SUBSTREAMS]; + AVPacket *in; + int ret, i, size, last_offset = 0; + int in_size, out_size; + int have_header = 0; + int substream_bits = 0; + int start, end; + uint16_t dts; + + ret = ff_bsf_get_packet(ctx, &in); + if (ret < 0) + return ret; + + if (in->size < 4) + goto fail; + + ret = init_get_bits(&gbc, in->data, 32); + if (ret < 0) + goto fail; + + skip_bits(&gbc, 4); + in_size = get_bits(&gbc, 12) * 2; + if (in_size < 4 || in_size > in->size) + goto fail; + + out_size = in_size; + dts = get_bits(&gbc, 16); + + ret = init_get_bits8(&gbc, in->data + 4, in->size - 4); + if (ret < 0) + goto fail; + + if (show_bits_long(&gbc, 32) == 0xf8726fba) { + if ((ret = ff_mlp_read_major_sync(ctx, &s->hdr, &gbc)) != 0) + goto fail; + have_header = 1; + } + + if (s->hdr.num_substreams > MAX_SUBSTREAMS) + goto fail; + + start = get_bits_count(&gbc); + for (i = 0; i < s->hdr.num_substreams; i++) { + for (int j = 0; j < 4; j++) + units[i].bits[j] = get_bits1(&gbc); + + units[i].offset = get_bits(&gbc, 12) * 2; + if (i < FFMIN(s->hdr.num_substreams, 3)) { + last_offset = units[i].offset; + substream_bits += 16; + } + + if (units[i].bits[0]) { + units[i].optional = get_bits(&gbc, 16); + if (i < FFMIN(s->hdr.num_substreams, 3)) + substream_bits += 16; + } + } + end = get_bits_count(&gbc); + + size = ((end + 7) >> 3) + 4 + last_offset; + if (size >= 0 && size <= in->size) + out_size = size; + if (out_size < in_size) { + int bpos = 0, reduce = (end - start - substream_bits) >> 4; + uint16_t parity_nibble = 0; + uint16_t auheader; + + ret = av_new_packet(out, out_size); + if (ret < 0) + goto fail; + + AV_WB16(out->data + 2, dts); + parity_nibble = dts; + out->size -= reduce * 2; + parity_nibble ^= out->size / 2; + + if (have_header) { + memcpy(out->data + 4, in->data + 4, 28); + out->data[16 + 4] = (out->data[16 + 4] & 0x0f) | (FFMIN(s->hdr.num_substreams, 3) << 4); + out->data[25 + 4] = out->data[25 + 4] & 0xfe; + out->data[26 + 4] = 0xff; + out->data[27 + 4] = 0xff; + AV_WL16(out->data + 4 + 26, ff_mlp_checksum16(out->data + 4, 26)); + } + + for (i = 0; i < FFMIN(s->hdr.num_substreams, 3); i++) { + uint16_t substr_hdr = 0; + + substr_hdr |= (units[i].bits[0] << 15); + substr_hdr |= (units[i].bits[1] << 14); + substr_hdr |= (units[i].bits[2] << 13); + substr_hdr |= (units[i].bits[3] << 12); + substr_hdr |= (units[i].offset / 2) & 0x0FFF; + + AV_WB16(out->data + have_header * 28 + 4 + bpos, substr_hdr); + + parity_nibble ^= out->data[have_header * 28 + 4 + bpos++]; + parity_nibble ^= out->data[have_header * 28 + 4 + bpos++]; + + if (units[i].bits[0]) { + AV_WB16(out->data + have_header * 28 + 4 + bpos, units[i].optional); + + parity_nibble ^= out->data[have_header * 28 + 4 + bpos++]; + parity_nibble ^= out->data[have_header * 28 + 4 + bpos++]; + } + } + + parity_nibble ^= parity_nibble >> 8; + parity_nibble ^= parity_nibble >> 4; + parity_nibble &= 0xF; + + memcpy(out->data + have_header * 28 + 4 + bpos, + in->data + 4 + (end >> 3), + out_size - (4 + (end >> 3))); + auheader = (parity_nibble ^ 0xF) << 12; + auheader |= (out->size / 2) & 0x0fff; + AV_WB16(out->data, auheader); + + ret = av_packet_copy_props(out, in); + } else { + av_packet_move_ref(out, in); + } + +fail: + if (ret < 0) + av_packet_unref(out); + av_packet_free(&in); + + return ret; +} + +static const enum AVCodecID codec_ids[] = { + AV_CODEC_ID_TRUEHD, AV_CODEC_ID_NONE, +}; + +const AVBitStreamFilter ff_truehd_core_bsf = { + .name = "truehd_core", + .priv_data_size = sizeof(TrueHDCoreContext), + .filter = truehd_core_filter, + .codec_ids = codec_ids, +}; |