[FFmpeg-devel] [PATCH] spdifenc: IEC 61937 encapsulation of DTS-HD for HDMI
Anssi Hannula
anssi.hannula
Sat Jan 29 02:36:30 CET 2011
---
Here's this patch again, modified for Justin's comments and rebased to
master (and tested it is still working).
Justin Ruggles wrote:
> I see quite a few "sizeof(dtshd_start_code) + 2 + pkt_size". Could
> these be factored out?
Actually, there were only 3 and the value of pkt_size may be different
for the first one. I now got rid of one by rearranging the lines a
little.
Changelog | 2 +-
libavformat/spdifenc.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++++
libavformat/version.h | 2 +-
3 files changed, 150 insertions(+), 2 deletions(-)
diff --git a/Changelog b/Changelog
index 8b7efb6..c4e565a 100644
--- a/Changelog
+++ b/Changelog
@@ -55,7 +55,7 @@ version <next>:
- Win64 support for optimized asm functions
- MJPEG/AVI1 to JPEG/JFIF bitstream filter
- ASS subtitle encoder and decoder
-- IEC 61937 encapsulation for E-AC3 and TrueHD (for HDMI passthrough)
+- IEC 61937 encapsulation for E-AC3, TrueHD, DTS-HD (for HDMI passthrough)
- overlay filter added
- rename aspect filter to setdar, and pixelaspect to setsar
- IEC 61937 demuxer
diff --git a/libavformat/spdifenc.c b/libavformat/spdifenc.c
index 3eea31e..3c6fd73 100644
--- a/libavformat/spdifenc.c
+++ b/libavformat/spdifenc.c
@@ -48,9 +48,12 @@
#include "spdif.h"
#include "libavcodec/ac3.h"
#include "libavcodec/dca.h"
+#include "libavcodec/dcadata.h"
#include "libavcodec/aacadtsdec.h"
+#include "libavutil/opt.h"
typedef struct IEC61937Context {
+ const AVClass *av_class;
enum IEC61937DataType data_type;///< burst info - reference to type of payload of the data-burst
int length_code; ///< length code in bits or bytes, depending on data type
int pkt_offset; ///< data burst repetition period in bytes
@@ -68,11 +71,24 @@ typedef struct IEC61937Context {
int hd_buf_count; ///< number of frames in the hd audio buffer
int hd_buf_filled; ///< amount of bytes in the hd audio buffer
+ int dtshd_skip; ///< counter used for skipping DTS-HD frames
+
+ /* AVOptions: */
+ int dtshd_rate;
+ int dtshd_fallback;
+
/// function, which generates codec dependent header information.
/// Sets data_type and pkt_offset, and length_code, out_bytes, out_buf if necessary
int (*header_info) (AVFormatContext *s, AVPacket *pkt);
} IEC61937Context;
+static const AVOption options[] = {
+{ "dtshd_rate", "mux complete DTS frames in HD mode at the specified IEC958 rate (in Hz, default 0=disabled)", offsetof(IEC61937Context, dtshd_rate), FF_OPT_TYPE_INT, 0, 0, 768000, AV_OPT_FLAG_ENCODING_PARAM },
+{ "dtshd_fallback_time", "min secs to strip HD for after an overflow (-1: till the end, default 60)", offsetof(IEC61937Context, dtshd_fallback), FF_OPT_TYPE_INT, 60, -1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
+{ NULL },
+};
+
+static const AVClass class = { "spdif", av_default_item_name, options, LIBAVUTIL_VERSION_INT };
static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt)
{
@@ -115,15 +131,125 @@ static int spdif_header_eac3(AVFormatContext *s, AVPacket *pkt)
return 0;
}
+/*
+ * DTS type IV (DTS-HD) can be transmitted with various frame repetition
+ * periods; longer repetition periods allow for longer packets and therefore
+ * higher bitrate. Longer repetition periods mean that the constant bitrate of
+ * the outputted IEC 61937 stream is higher.
+ * The repetition period is measured in IEC 60958 frames (4 bytes).
+ */
+enum {
+ DTS4_REP_PER_512 = 0x0,
+ DTS4_REP_PER_1024 = 0x1,
+ DTS4_REP_PER_2048 = 0x2,
+ DTS4_REP_PER_4096 = 0x3,
+ DTS4_REP_PER_8192 = 0x4,
+ DTS4_REP_PER_16384 = 0x5,
+};
+
+static int spdif_dts4_subtype(int period)
+{
+ switch (period) {
+ case 512: return DTS4_REP_PER_512;
+ case 1024: return DTS4_REP_PER_1024;
+ case 2048: return DTS4_REP_PER_2048;
+ case 4096: return DTS4_REP_PER_4096;
+ case 8192: return DTS4_REP_PER_8192;
+ case 16384: return DTS4_REP_PER_16384;
+ }
+ return -1;
+}
+
+static int spdif_header_dts4(AVFormatContext *s, AVPacket *pkt, int core_size,
+ int sample_rate, int blocks)
+{
+ IEC61937Context *ctx = s->priv_data;
+ static const char dtshd_start_code[10] = { 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfe, 0xfe };
+ int pkt_size = pkt->size;
+ int period;
+ int subtype;
+
+ if (!core_size) {
+ av_log(s, AV_LOG_ERROR, "HD mode not supported for this format\n");
+ return AVERROR(EINVAL);
+ }
+
+ if (!sample_rate) {
+ av_log(s, AV_LOG_ERROR, "Unknown DTS sample rate for HD\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ period = ctx->dtshd_rate * (blocks << 5) / sample_rate;
+ subtype = spdif_dts4_subtype(period);
+
+ if (subtype < 0) {
+ av_log(s, AV_LOG_ERROR, "Specified HD rate of %d Hz would require an "
+ "impossible repetition period of %d for the current DTS stream"
+ " (blocks = %d, sample rate = %d)\n", ctx->dtshd_rate, period,
+ blocks << 5, sample_rate);
+ return AVERROR(EINVAL);
+ }
+
+ /* set pkt_offset and DTS IV subtype according to the requested output
+ * rate */
+ ctx->pkt_offset = period * 4;
+ ctx->data_type = IEC61937_DTSHD | subtype << 8;
+
+ /* If the bitrate is too high for transmitting at the selected
+ * repetition period setting, strip DTS-HD until a good amount
+ * of consecutive non-overflowing HD frames have been observed.
+ * This generally only happens if the caller is cramming a Master
+ * Audio stream into 192kHz IEC 60958 (which may or may not fit). */
+ if (sizeof(dtshd_start_code) + 2 + pkt_size
+ > ctx->pkt_offset - BURST_HEADER_SIZE && core_size) {
+ if (!ctx->dtshd_skip)
+ av_log(s, AV_LOG_WARNING, "DTS-HD bitrate too high, "
+ "temporarily sending core only\n");
+ if (ctx->dtshd_fallback > 0)
+ ctx->dtshd_skip = sample_rate * ctx->dtshd_fallback / (blocks << 5);
+ else
+ /* skip permanently (-1) or just once (0) */
+ ctx->dtshd_skip = 1;
+ }
+ if (ctx->dtshd_skip && core_size) {
+ pkt_size = core_size;
+ if (ctx->dtshd_fallback >= 0)
+ --ctx->dtshd_skip;
+ }
+
+ ctx->out_bytes = sizeof(dtshd_start_code) + 2 + pkt_size;
+ ctx->length_code = ctx->out_bytes;
+
+ ctx->hd_buf = av_fast_realloc(ctx->hd_buf, &ctx->hd_buf_size,
+ ctx->out_bytes);
+ if (!ctx->hd_buf)
+ return AVERROR(ENOMEM);
+
+ ctx->out_buf = ctx->hd_buf;
+
+ memcpy(ctx->hd_buf, dtshd_start_code, sizeof(dtshd_start_code));
+ AV_WB16(ctx->hd_buf + sizeof(dtshd_start_code), pkt_size);
+ memcpy(ctx->hd_buf + sizeof(dtshd_start_code) + 2, pkt->data, pkt_size);
+
+ return 0;
+}
+
static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
{
IEC61937Context *ctx = s->priv_data;
uint32_t syncword_dts = AV_RB32(pkt->data);
int blocks;
+ int sample_rate = 0;
+ int core_size = 0;
+
+ if (pkt->size < 9)
+ return AVERROR_INVALIDDATA;
switch (syncword_dts) {
case DCA_MARKER_RAW_BE:
blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f;
+ core_size = ((AV_RB24(pkt->data + 5) >> 4) & 0x3fff) + 1;
+ sample_rate = dca_sample_rates[(pkt->data[8] >> 2) & 0x0f];
break;
case DCA_MARKER_RAW_LE:
blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f;
@@ -138,11 +264,22 @@ static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
(((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2));
ctx->extra_bswap = 1;
break;
+ case DCA_HD_MARKER:
+ /* We only handle HD frames that are paired with core. However,
+ sometimes DTS-HD streams with core have a stray HD frame without
+ core in the beginning of the stream. */
+ av_log(s, AV_LOG_ERROR, "stray DTS-HD frame\n");
+ return AVERROR_INVALIDDATA;
default:
av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%x\n", syncword_dts);
return AVERROR_INVALIDDATA;
}
blocks++;
+
+ if (ctx->dtshd_rate)
+ /* DTS type IV output requested */
+ return spdif_header_dts4(s, pkt, core_size, sample_rate, blocks);
+
switch (blocks) {
case 512 >> 5: ctx->data_type = IEC61937_DTS1; break;
case 1024 >> 5: ctx->data_type = IEC61937_DTS2; break;
@@ -152,6 +289,13 @@ static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
blocks << 5);
return AVERROR(ENOSYS);
}
+
+ /* discard extraneous data by default */
+ if (core_size && core_size < pkt->size) {
+ ctx->out_bytes = core_size;
+ ctx->length_code = core_size << 3;
+ }
+
ctx->pkt_offset = blocks << 7;
if (ctx->out_bytes == ctx->pkt_offset) {
@@ -159,6 +303,9 @@ static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
* preamble as it would not fit in there. This is the case for dts
* discs and dts-in-wav. */
ctx->use_preamble = 0;
+ } else if (ctx->out_bytes > ctx->pkt_offset - BURST_HEADER_SIZE) {
+ av_log_ask_for_sample(s, "Unrecognized large DTS frame.");
+ /* This will fail with a "bitrate too high" in the caller */
}
return 0;
@@ -393,4 +540,5 @@ AVOutputFormat ff_spdif_muxer = {
spdif_write_header,
spdif_write_packet,
spdif_write_trailer,
+ .priv_class = &class,
};
diff --git a/libavformat/version.h b/libavformat/version.h
index 9a902aa..807bcb3 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -25,7 +25,7 @@
#define LIBAVFORMAT_VERSION_MAJOR 52
#define LIBAVFORMAT_VERSION_MINOR 94
-#define LIBAVFORMAT_VERSION_MICRO 0
+#define LIBAVFORMAT_VERSION_MICRO 1
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
LIBAVFORMAT_VERSION_MINOR, \
--
1.7.3
More information about the ffmpeg-devel
mailing list