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FFmpeg/libavformat/spdif.c
Bartlomiej Wolowiec ab1eff9c5c Add support for S/PDIF encapsulation. 
Originally committed as revision 19674 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-08-21 08:34:19 +00:00

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/*
* IEC958 muxer
* Copyright (c) 2009 Bartlomiej Wolowiec
*
* 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
*/
/**
* @file libavformat/spdif.c
* IEC-61937 encapsulation of various formats, used by S/PDIF
* @author Bartlomiej Wolowiec
*/
/*
* Terminology used in specification:
* data-burst - IEC958 frame, contains header and encapsuled frame
* burst-preambule - IEC958 frame header, contains 16-bits words named Pa, Pb, Pc and Pd
* burst-payload - encapsuled frame
* Pa, Pb - syncword - 0xF872, 0x4E1F
* Pc - burst-info, contains data-type (bits 0-6), error flag (bit 7), data-type-dependent info (bits 8-12)
* and bitstream number (bits 13-15)
* data-type - determines type of encapsuled frames
* Pd - length code (number of bits or bytes of encapsuled frame - according to data_type)
*
* IEC958 frames at normal usage start every specific count of bytes,
* dependent from data-type (spaces between packets are filled by zeros)
*/
#include "avformat.h"
#include "libavcodec/ac3.h"
#include "libavcodec/dca.h"
#include "libavcodec/aac_parser.h"
#define SYNCWORD1 0xF872
#define SYNCWORD2 0x4E1F
#define BURST_HEADER_SIZE 0x8
enum IEC958DataType {
IEC958_AC3 = 0x01, ///< AC-3 data
IEC958_MPEG1_LAYER1 = 0x04, ///< MPEG-1 layer 1
IEC958_MPEG1_LAYER23 = 0x05, ///< MPEG-1 layer 2 or 3 data or MPEG-2 without extension
IEC958_MPEG2_EXT = 0x06, ///< MPEG-2 data with extension
IEC958_MPEG2_AAC = 0x07, ///< MPEG-2 AAC ADTS
IEC958_MPEG2_LAYER1_LSF = 0x08, ///< MPEG-2, layer-1 low sampling frequency
IEC958_MPEG2_LAYER2_LSF = 0x09, ///< MPEG-2, layer-2 low sampling frequency
IEC958_MPEG2_LAYER3_LSF = 0x0A, ///< MPEG-2, layer-3 low sampling frequency
IEC958_DTS1 = 0x0B, ///< DTS type I (512 samples)
IEC958_DTS2 = 0x0C, ///< DTS type II (1024 samples)
IEC958_DTS3 = 0x0D, ///< DTS type III (2048 samples)
IEC958_MPEG2_AAC_LSF_2048 = 0x13, ///< MPEG-2 AAC ADTS half-rate low sampling frequency
IEC958_MPEG2_AAC_LSF_4096 = 0x13 | 0x20, ///< MPEG-2 AAC ADTS quarter-rate low sampling frequency
};
typedef struct IEC958Context {
enum IEC958DataType data_type; ///< burst info - reference to type of payload of the data-burst
int pkt_size; ///< length code in bits
int pkt_offset; ///< data burst repetition period in bytes
uint8_t *buffer; ///< allocated buffer, used for swap bytes
int buffer_size; ///< size of allocated buffer
/// function, which generates codec dependent header information.
/// Sets data_type and data_offset
int (*header_info) (AVFormatContext *s, AVPacket *pkt);
} IEC958Context;
//TODO move to DSP
static void bswap_buf16(uint16_t *dst, const uint16_t *src, int w)
{
int i;
for (i = 0; i + 8 <= w; i += 8) {
dst[i + 0] = bswap_16(src[i + 0]);
dst[i + 1] = bswap_16(src[i + 1]);
dst[i + 2] = bswap_16(src[i + 2]);
dst[i + 3] = bswap_16(src[i + 3]);
dst[i + 4] = bswap_16(src[i + 4]);
dst[i + 5] = bswap_16(src[i + 5]);
dst[i + 6] = bswap_16(src[i + 6]);
dst[i + 7] = bswap_16(src[i + 7]);
}
for (; i < w; i++)
dst[i + 0] = bswap_16(src[i + 0]);
}
static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt)
{
IEC958Context *ctx = s->priv_data;
int bitstream_mode = pkt->data[6] & 0x7;
ctx->data_type = IEC958_AC3 | (bitstream_mode << 8);
ctx->pkt_offset = AC3_FRAME_SIZE << 2;
return 0;
}
static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
{
IEC958Context *ctx = s->priv_data;
uint32_t syncword_dts = AV_RB32(pkt->data);
int blocks;
switch (syncword_dts) {
case DCA_MARKER_RAW_BE:
blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f;
break;
case DCA_MARKER_RAW_LE:
blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f;
break;
case DCA_MARKER_14B_BE:
blocks =
(((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2));
break;
case DCA_MARKER_14B_LE:
blocks =
(((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2));
break;
default:
av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%x\n", syncword_dts);
return -1;
}
blocks++;
switch (blocks) {
case 512 >> 5: ctx->data_type = IEC958_DTS1; break;
case 1024 >> 5: ctx->data_type = IEC958_DTS2; break;
case 2048 >> 5: ctx->data_type = IEC958_DTS3; break;
default:
av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n",
blocks << 5);
return -1;
}
ctx->pkt_offset = blocks << 7;
return 0;
}
static const enum IEC958DataType mpeg_data_type[2][3] = {
// LAYER1 LAYER2 LAYER3
{ IEC958_MPEG2_LAYER1_LSF, IEC958_MPEG2_LAYER2_LSF, IEC958_MPEG2_LAYER3_LSF }, //MPEG2 LSF
{ IEC958_MPEG1_LAYER1, IEC958_MPEG1_LAYER23, IEC958_MPEG1_LAYER23 }, //MPEG1
};
static const uint16_t mpeg_pkt_offset[2][3] = {
//LAYER1 LAYER2 LAYER3
{ 3072, 9216, 4608 }, // MPEG2 LSF
{ 1536, 4608, 4608 }, // MPEG1
};
static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt)
{
IEC958Context *ctx = s->priv_data;
int version = (pkt->data[1] >> 3) & 3;
int layer = 3 - ((pkt->data[1] >> 1) & 3);
int extension = pkt->data[2] & 1;
if (layer == 3 || version == 1) {
av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n");
return -1;
}
av_log(s, AV_LOG_DEBUG, "version: %i layer: %i extension: %i\n", version, layer, extension);
if (version == 2 && extension) {
ctx->data_type = IEC958_MPEG2_EXT;
ctx->pkt_offset = 4608;
} else {
ctx->data_type = mpeg_data_type [version & 1][layer];
ctx->pkt_offset = mpeg_pkt_offset[version & 1][layer];
}
// TODO Data type dependant info (normal/karaoke, dynamic range control)
return 0;
}
static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt)
{
IEC958Context *ctx = s->priv_data;
AACADTSHeaderInfo hdr;
GetBitContext gbc;
int ret;
init_get_bits(&gbc, pkt->data, AAC_ADTS_HEADER_SIZE * 8);
ret = ff_aac_parse_header(&gbc, &hdr);
if (ret < 0) {
av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n");
return -1;
}
ctx->pkt_offset = hdr.samples << 2;
switch (hdr.num_aac_frames) {
case 1:
ctx->data_type = IEC958_MPEG2_AAC;
break;
case 2:
ctx->data_type = IEC958_MPEG2_AAC_LSF_2048;
break;
case 4:
ctx->data_type = IEC958_MPEG2_AAC_LSF_4096;
break;
default:
av_log(s, AV_LOG_ERROR, "%i samples in AAC frame not supported\n",
hdr.samples);
return -1;
}
//TODO Data type dependent info (LC profile/SBR)
return 0;
}
static int spdif_write_header(AVFormatContext *s)
{
IEC958Context *ctx = s->priv_data;
switch (s->streams[0]->codec->codec_id) {
case CODEC_ID_AC3:
ctx->header_info = spdif_header_ac3;
break;
case CODEC_ID_MP1:
case CODEC_ID_MP2:
case CODEC_ID_MP3:
ctx->header_info = spdif_header_mpeg;
break;
case CODEC_ID_DTS:
ctx->header_info = spdif_header_dts;
break;
case CODEC_ID_AAC:
ctx->header_info = spdif_header_aac;
break;
default:
av_log(s, AV_LOG_ERROR, "codec not supported\n");
return -1;
}
put_le16(s->pb, 0);
put_le16(s->pb, 0);
put_le16(s->pb, 0);
put_le16(s->pb, 0);
return 0;
}
static int spdif_write_trailer(AVFormatContext *s)
{
IEC958Context *ctx = s->priv_data;
av_freep(&ctx->buffer);
return 0;
}
static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt)
{
IEC958Context *ctx = s->priv_data;
int ret, padding;
ctx->pkt_size = FFALIGN(pkt->size, 2) << 3;
ret = ctx->header_info(s, pkt);
if (ret < 0)
return -1;
padding = (ctx->pkt_offset - BURST_HEADER_SIZE - pkt->size) >> 1;
if (padding < 0) {
av_log(s, AV_LOG_ERROR, "bitrate is too high\n");
return -1;
}
put_le16(s->pb, SYNCWORD1); //Pa
put_le16(s->pb, SYNCWORD2); //Pb
put_le16(s->pb, ctx->data_type); //Pc
put_le16(s->pb, ctx->pkt_size); //Pd
#if HAVE_BIGENDIAN
put_buffer(s->pb, pkt->data, pkt->size & ~1);
#else
av_fast_malloc(&ctx->buffer, &ctx->buffer_size, pkt->size + FF_INPUT_BUFFER_PADDING_SIZE);
if (!ctx->buffer)
return AVERROR(ENOMEM);
bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)pkt->data, pkt->size >> 1);
put_buffer(s->pb, ctx->buffer, pkt->size & ~1);
#endif
if (pkt->size & 1)
put_be16(s->pb, pkt->data[pkt->size - 1]);
for (; padding > 0; padding--)
put_be16(s->pb, 0);
av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n",
ctx->data_type, pkt->size, ctx->pkt_offset);
put_flush_packet(s->pb);
return 0;
}
AVOutputFormat spdif_muxer = {
"spdif",
NULL_IF_CONFIG_SMALL("IEC958 - S/PDIF (IEC-61937)"),
NULL,
"spdif",
sizeof(IEC958Context),
CODEC_ID_AC3,
CODEC_ID_NONE,
spdif_write_header,
spdif_write_packet,
spdif_write_trailer,
};
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