yading@10: /*
yading@10:  * MLP parser
yading@10:  * Copyright (c) 2007 Ian Caulfield
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:  * MLP parser
yading@10:  */
yading@10: 
yading@10: #include <stdint.h>
yading@10: 
yading@10: #include "libavutil/channel_layout.h"
yading@10: #include "libavutil/crc.h"
yading@10: #include "get_bits.h"
yading@10: #include "parser.h"
yading@10: #include "mlp_parser.h"
yading@10: #include "mlp.h"
yading@10: 
yading@10: static const uint8_t mlp_quants[16] = {
yading@10:     16, 20, 24, 0, 0, 0, 0, 0,
yading@10:      0,  0,  0, 0, 0, 0, 0, 0,
yading@10: };
yading@10: 
yading@10: static const uint8_t mlp_channels[32] = {
yading@10:     1, 2, 3, 4, 3, 4, 5, 3, 4, 5, 4, 5, 6, 4, 5, 4,
yading@10:     5, 6, 5, 5, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
yading@10: };
yading@10: 
yading@10: const uint64_t ff_mlp_layout[32] = {
yading@10:     AV_CH_LAYOUT_MONO,
yading@10:     AV_CH_LAYOUT_STEREO,
yading@10:     AV_CH_LAYOUT_2_1,
yading@10:     AV_CH_LAYOUT_QUAD,
yading@10:     AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,
yading@10:     AV_CH_LAYOUT_2_1|AV_CH_LOW_FREQUENCY,
yading@10:     AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY,
yading@10:     AV_CH_LAYOUT_SURROUND,
yading@10:     AV_CH_LAYOUT_4POINT0,
yading@10:     AV_CH_LAYOUT_5POINT0_BACK,
yading@10:     AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
yading@10:     AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
yading@10:     AV_CH_LAYOUT_5POINT1_BACK,
yading@10:     AV_CH_LAYOUT_4POINT0,
yading@10:     AV_CH_LAYOUT_5POINT0_BACK,
yading@10:     AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
yading@10:     AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
yading@10:     AV_CH_LAYOUT_5POINT1_BACK,
yading@10:     AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY,
yading@10:     AV_CH_LAYOUT_5POINT0_BACK,
yading@10:     AV_CH_LAYOUT_5POINT1_BACK,
yading@10:     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
yading@10: };
yading@10: 
yading@10: static const uint8_t thd_chancount[13] = {
yading@10: //  LR    C   LFE  LRs LRvh  LRc LRrs  Cs   Ts  LRsd  LRw  Cvh  LFE2
yading@10:      2,   1,   1,   2,   2,   2,   2,   1,   1,   2,   2,   1,   1
yading@10: };
yading@10: 
yading@10: static const uint64_t thd_layout[13] = {
yading@10:     AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT,                     // LR
yading@10:     AV_CH_FRONT_CENTER,                                     // C
yading@10:     AV_CH_LOW_FREQUENCY,                                    // LFE
yading@10:     AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT,                       // LRs
yading@10:     AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT,             // LRvh
yading@10:     AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER, // LRc
yading@10:     AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT,                       // LRrs
yading@10:     AV_CH_BACK_CENTER,                                      // Cs
yading@10:     AV_CH_TOP_CENTER,                                       // Ts
yading@10:     AV_CH_SURROUND_DIRECT_LEFT|AV_CH_SURROUND_DIRECT_RIGHT, // LRsd
yading@10:     AV_CH_WIDE_LEFT|AV_CH_WIDE_RIGHT,                       // LRw
yading@10:     AV_CH_TOP_FRONT_CENTER,                                 // Cvh
yading@10:     AV_CH_LOW_FREQUENCY_2,                                  // LFE2
yading@10: };
yading@10: 
yading@10: static int mlp_samplerate(int in)
yading@10: {
yading@10:     if (in == 0xF)
yading@10:         return 0;
yading@10: 
yading@10:     return (in & 8 ? 44100 : 48000) << (in & 7) ;
yading@10: }
yading@10: 
yading@10: static int truehd_channels(int chanmap)
yading@10: {
yading@10:     int channels = 0, i;
yading@10: 
yading@10:     for (i = 0; i < 13; i++)
yading@10:         channels += thd_chancount[i] * ((chanmap >> i) & 1);
yading@10: 
yading@10:     return channels;
yading@10: }
yading@10: 
yading@10: uint64_t ff_truehd_layout(int chanmap)
yading@10: {
yading@10:     int i;
yading@10:     uint64_t layout = 0;
yading@10: 
yading@10:     for (i = 0; i < 13; i++)
yading@10:         layout |= thd_layout[i] * ((chanmap >> i) & 1);
yading@10: 
yading@10:     return layout;
yading@10: }
yading@10: 
yading@10: /** Read a major sync info header - contains high level information about
yading@10:  *  the stream - sample rate, channel arrangement etc. Most of this
yading@10:  *  information is not actually necessary for decoding, only for playback.
yading@10:  *  gb must be a freshly initialized GetBitContext with no bits read.
yading@10:  */
yading@10: 
yading@10: int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, GetBitContext *gb)
yading@10: {
yading@10:     int ratebits, channel_arrangement;
yading@10:     uint16_t checksum;
yading@10: 
yading@10:     av_assert1(get_bits_count(gb) == 0);
yading@10: 
yading@10:     if (gb->size_in_bits < 28 << 3) {
yading@10:         av_log(log, AV_LOG_ERROR, "packet too short, unable to read major sync\n");
yading@10:         return -1;
yading@10:     }
yading@10: 
yading@10:     checksum = ff_mlp_checksum16(gb->buffer, 26);
yading@10:     if (checksum != AV_RL16(gb->buffer+26)) {
yading@10:         av_log(log, AV_LOG_ERROR, "major sync info header checksum error\n");
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     if (get_bits_long(gb, 24) != 0xf8726f) /* Sync words */
yading@10:         return AVERROR_INVALIDDATA;
yading@10: 
yading@10:     mh->stream_type = get_bits(gb, 8);
yading@10: 
yading@10:     if (mh->stream_type == 0xbb) {
yading@10:         mh->group1_bits = mlp_quants[get_bits(gb, 4)];
yading@10:         mh->group2_bits = mlp_quants[get_bits(gb, 4)];
yading@10: 
yading@10:         ratebits = get_bits(gb, 4);
yading@10:         mh->group1_samplerate = mlp_samplerate(ratebits);
yading@10:         mh->group2_samplerate = mlp_samplerate(get_bits(gb, 4));
yading@10: 
yading@10:         skip_bits(gb, 11);
yading@10: 
yading@10:         mh->channel_arrangement=
yading@10:         channel_arrangement    = get_bits(gb, 5);
yading@10:         mh->channels_mlp       = mlp_channels[channel_arrangement];
yading@10:         mh->channel_layout_mlp = ff_mlp_layout[channel_arrangement];
yading@10:     } else if (mh->stream_type == 0xba) {
yading@10:         mh->group1_bits = 24; // TODO: Is this information actually conveyed anywhere?
yading@10:         mh->group2_bits = 0;
yading@10: 
yading@10:         ratebits = get_bits(gb, 4);
yading@10:         mh->group1_samplerate = mlp_samplerate(ratebits);
yading@10:         mh->group2_samplerate = 0;
yading@10: 
yading@10:         skip_bits(gb, 8);
yading@10: 
yading@10:         mh->channel_arrangement=
yading@10:         channel_arrangement            = get_bits(gb, 5);
yading@10:         mh->channels_thd_stream1       = truehd_channels(channel_arrangement);
yading@10:         mh->channel_layout_thd_stream1 = ff_truehd_layout(channel_arrangement);
yading@10: 
yading@10:         skip_bits(gb, 2);
yading@10: 
yading@10:         channel_arrangement            = get_bits(gb, 13);
yading@10:         mh->channels_thd_stream2       = truehd_channels(channel_arrangement);
yading@10:         mh->channel_layout_thd_stream2 = ff_truehd_layout(channel_arrangement);
yading@10:     } else
yading@10:         return AVERROR_INVALIDDATA;
yading@10: 
yading@10:     mh->access_unit_size = 40 << (ratebits & 7);
yading@10:     mh->access_unit_size_pow2 = 64 << (ratebits & 7);
yading@10: 
yading@10:     skip_bits_long(gb, 48);
yading@10: 
yading@10:     mh->is_vbr = get_bits1(gb);
yading@10: 
yading@10:     mh->peak_bitrate = (get_bits(gb, 15) * mh->group1_samplerate + 8) >> 4;
yading@10: 
yading@10:     mh->num_substreams = get_bits(gb, 4);
yading@10: 
yading@10:     skip_bits_long(gb, 4 + 11 * 8);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: typedef struct MLPParseContext
yading@10: {
yading@10:     ParseContext pc;
yading@10: 
yading@10:     int bytes_left;
yading@10: 
yading@10:     int in_sync;
yading@10: 
yading@10:     int num_substreams;
yading@10: } MLPParseContext;
yading@10: 
yading@10: static av_cold int mlp_init(AVCodecParserContext *s)
yading@10: {
yading@10:     ff_mlp_init_crc();
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int mlp_parse(AVCodecParserContext *s,
yading@10:                      AVCodecContext *avctx,
yading@10:                      const uint8_t **poutbuf, int *poutbuf_size,
yading@10:                      const uint8_t *buf, int buf_size)
yading@10: {
yading@10:     MLPParseContext *mp = s->priv_data;
yading@10:     int sync_present;
yading@10:     uint8_t parity_bits;
yading@10:     int next;
yading@10:     int i, p = 0;
yading@10: 
yading@10:     *poutbuf_size = 0;
yading@10:     if (buf_size == 0)
yading@10:         return 0;
yading@10: 
yading@10:     if (!mp->in_sync) {
yading@10:         // Not in sync - find a major sync header
yading@10: 
yading@10:         for (i = 0; i < buf_size; i++) {
yading@10:             mp->pc.state = (mp->pc.state << 8) | buf[i];
yading@10:             if ((mp->pc.state & 0xfffffffe) == 0xf8726fba &&
yading@10:                 // ignore if we do not have the data for the start of header
yading@10:                 mp->pc.index + i >= 7) {
yading@10:                 mp->in_sync = 1;
yading@10:                 mp->bytes_left = 0;
yading@10:                 break;
yading@10:             }
yading@10:         }
yading@10: 
yading@10:         if (!mp->in_sync) {
yading@10:             if (ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size) != -1)
yading@10:                 av_log(avctx, AV_LOG_WARNING, "ff_combine_frame failed\n");
yading@10:             return buf_size;
yading@10:         }
yading@10: 
yading@10:         ff_combine_frame(&mp->pc, i - 7, &buf, &buf_size);
yading@10: 
yading@10:         return i - 7;
yading@10:     }
yading@10: 
yading@10:     if (mp->bytes_left == 0) {
yading@10:         // Find length of this packet
yading@10: 
yading@10:         /* Copy overread bytes from last frame into buffer. */
yading@10:         for(; mp->pc.overread>0; mp->pc.overread--) {
yading@10:             mp->pc.buffer[mp->pc.index++]= mp->pc.buffer[mp->pc.overread_index++];
yading@10:         }
yading@10: 
yading@10:         if (mp->pc.index + buf_size < 2) {
yading@10:             if (ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size) != -1)
yading@10:                 av_log(avctx, AV_LOG_WARNING, "ff_combine_frame failed\n");
yading@10:             return buf_size;
yading@10:         }
yading@10: 
yading@10:         mp->bytes_left = ((mp->pc.index > 0 ? mp->pc.buffer[0] : buf[0]) << 8)
yading@10:                        |  (mp->pc.index > 1 ? mp->pc.buffer[1] : buf[1-mp->pc.index]);
yading@10:         mp->bytes_left = (mp->bytes_left & 0xfff) * 2;
yading@10:         if (mp->bytes_left <= 0) { // prevent infinite loop
yading@10:             goto lost_sync;
yading@10:         }
yading@10:         mp->bytes_left -= mp->pc.index;
yading@10:     }
yading@10: 
yading@10:     next = (mp->bytes_left > buf_size) ? END_NOT_FOUND : mp->bytes_left;
yading@10: 
yading@10:     if (ff_combine_frame(&mp->pc, next, &buf, &buf_size) < 0) {
yading@10:         mp->bytes_left -= buf_size;
yading@10:         return buf_size;
yading@10:     }
yading@10: 
yading@10:     mp->bytes_left = 0;
yading@10: 
yading@10:     sync_present = (AV_RB32(buf + 4) & 0xfffffffe) == 0xf8726fba;
yading@10: 
yading@10:     if (!sync_present) {
yading@10:         /* The first nibble of a frame is a parity check of the 4-byte
yading@10:          * access unit header and all the 2- or 4-byte substream headers. */
yading@10:         // Only check when this isn't a sync frame - syncs have a checksum.
yading@10: 
yading@10:         parity_bits = 0;
yading@10:         for (i = -1; i < mp->num_substreams; i++) {
yading@10:             parity_bits ^= buf[p++];
yading@10:             parity_bits ^= buf[p++];
yading@10: 
yading@10:             if (i < 0 || buf[p-2] & 0x80) {
yading@10:                 parity_bits ^= buf[p++];
yading@10:                 parity_bits ^= buf[p++];
yading@10:             }
yading@10:         }
yading@10: 
yading@10:         if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) {
yading@10:             av_log(avctx, AV_LOG_INFO, "mlpparse: Parity check failed.\n");
yading@10:             goto lost_sync;
yading@10:         }
yading@10:     } else {
yading@10:         GetBitContext gb;
yading@10:         MLPHeaderInfo mh;
yading@10: 
yading@10:         init_get_bits(&gb, buf + 4, (buf_size - 4) << 3);
yading@10:         if (ff_mlp_read_major_sync(avctx, &mh, &gb) < 0)
yading@10:             goto lost_sync;
yading@10: 
yading@10:         avctx->bits_per_raw_sample = mh.group1_bits;
yading@10:         if (avctx->bits_per_raw_sample > 16)
yading@10:             avctx->sample_fmt = AV_SAMPLE_FMT_S32;
yading@10:         else
yading@10:             avctx->sample_fmt = AV_SAMPLE_FMT_S16;
yading@10:         avctx->sample_rate = mh.group1_samplerate;
yading@10:         s->duration = mh.access_unit_size;
yading@10: 
yading@10:         if(!avctx->channels || !avctx->channel_layout) {
yading@10:         if (mh.stream_type == 0xbb) {
yading@10:             /* MLP stream */
yading@10: #if FF_API_REQUEST_CHANNELS
yading@10:             if (avctx->request_channels > 0 && avctx->request_channels <= 2 &&
yading@10:                 mh.num_substreams > 1) {
yading@10:                 avctx->channels       = 2;
yading@10:                 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
yading@10:             } else
yading@10: #endif
yading@10:             if (avctx->request_channel_layout == AV_CH_LAYOUT_STEREO &&
yading@10:                 mh.num_substreams > 1) {
yading@10:                 avctx->channels       = 2;
yading@10:                 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
yading@10:             } else {
yading@10:                 avctx->channels       = mh.channels_mlp;
yading@10:                 avctx->channel_layout = mh.channel_layout_mlp;
yading@10:             }
yading@10:         } else { /* mh.stream_type == 0xba */
yading@10:             /* TrueHD stream */
yading@10: #if FF_API_REQUEST_CHANNELS
yading@10:             if (avctx->request_channels > 0 && avctx->request_channels <= 2 &&
yading@10:                 mh.num_substreams > 1) {
yading@10:                 avctx->channels       = 2;
yading@10:                 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
yading@10:             } else if (avctx->request_channels > 0 &&
yading@10:                        avctx->request_channels <= mh.channels_thd_stream1) {
yading@10:                 avctx->channels       = mh.channels_thd_stream1;
yading@10:                 avctx->channel_layout = mh.channel_layout_thd_stream1;
yading@10:             } else
yading@10: #endif
yading@10:             if (avctx->request_channel_layout == AV_CH_LAYOUT_STEREO &&
yading@10:                 mh.num_substreams > 1) {
yading@10:                 avctx->channels       = 2;
yading@10:                 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
yading@10:             } else if (avctx->request_channel_layout == mh.channel_layout_thd_stream1 ||
yading@10:                        !mh.channels_thd_stream2) {
yading@10:                 avctx->channels       = mh.channels_thd_stream1;
yading@10:                 avctx->channel_layout = mh.channel_layout_thd_stream1;
yading@10:             } else {
yading@10:                 avctx->channels       = mh.channels_thd_stream2;
yading@10:                 avctx->channel_layout = mh.channel_layout_thd_stream2;
yading@10:             }
yading@10:         }
yading@10:         }
yading@10: 
yading@10:         if (!mh.is_vbr) /* Stream is CBR */
yading@10:             avctx->bit_rate = mh.peak_bitrate;
yading@10: 
yading@10:         mp->num_substreams = mh.num_substreams;
yading@10:     }
yading@10: 
yading@10:     *poutbuf = buf;
yading@10:     *poutbuf_size = buf_size;
yading@10: 
yading@10:     return next;
yading@10: 
yading@10: lost_sync:
yading@10:     mp->in_sync = 0;
yading@10:     return 1;
yading@10: }
yading@10: 
yading@10: AVCodecParser ff_mlp_parser = {
yading@10:     .codec_ids      = { AV_CODEC_ID_MLP, AV_CODEC_ID_TRUEHD },
yading@10:     .priv_data_size = sizeof(MLPParseContext),
yading@10:     .parser_init    = mlp_init,
yading@10:     .parser_parse   = mlp_parse,
yading@10:     .parser_close   = ff_parse_close,
yading@10: };