From bb47aa5850c8f31939a978d361c834d1f3a53960 Mon Sep 17 00:00:00 2001 From: Vignesh Venkatasubramanian Date: Fri, 30 Aug 2013 11:26:37 -0700 Subject: [PATCH] opus/matroska: Adding support for DiscardPadding in muxer Support for end trimming Opus in Matroska is implemented by using the DiscardPadding container element in the Block data. The last chunk is stored as a Block instead of SimpleBlock and the trimming information is stored and used to discard samples that were padded by the Opus codec. This patch adds support for muxing DiscardPadding element into the container with appropriate value. Matroska spec for the DiscardPadding element can be found here: http://matroska.org/technical/specs/index.html#DiscardPadding Signed-off-by: Vignesh Venkatasubramanian Signed-off-by: Michael Niedermayer --- libavformat/matroska.h | 1 + libavformat/matroskaenc.c | 24 ++++++++++++++++++++++-- 2 files changed, 23 insertions(+), 2 deletions(-) diff --git a/libavformat/matroska.h b/libavformat/matroska.h index 7cf423c502..002fc4cbc9 100644 --- a/libavformat/matroska.h +++ b/libavformat/matroska.h @@ -198,6 +198,7 @@ #define MATROSKA_ID_BLOCKDURATION 0x9B #define MATROSKA_ID_BLOCKREFERENCE 0xFB #define MATROSKA_ID_CODECSTATE 0xA4 +#define MATROSKA_ID_DISCARDPADDING 0x75A2 /* IDs in the attachments master */ #define MATROSKA_ID_ATTACHEDFILE 0x61A7 diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c index 2c128ccbb7..973076103a 100644 --- a/libavformat/matroskaenc.c +++ b/libavformat/matroskaenc.c @@ -44,6 +44,7 @@ #include "libavcodec/xiph.h" #include "libavcodec/mpeg4audio.h" +#include "libavcodec/internal.h" typedef struct ebml_master { int64_t pos; ///< absolute offset in the file where the master's elements start @@ -1289,7 +1290,7 @@ static void mkv_write_block(AVFormatContext *s, AVIOContext *pb, uint8_t *data = NULL, *side_data = NULL; int offset = 0, size = pkt->size, side_data_size = 0; int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts; - uint64_t additional_id = 0; + uint64_t additional_id = 0, discard_padding = 0; ebml_master block_group, block_additions, block_more; av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, " @@ -1314,6 +1315,16 @@ static void mkv_write_block(AVFormatContext *s, AVIOContext *pb, offset = 8; } + side_data = av_packet_get_side_data(pkt, + AV_PKT_DATA_SKIP_SAMPLES, + &side_data_size); + + if (side_data && side_data_size >= 10) { + discard_padding = av_rescale_q(AV_RL32(side_data + 4), + (AVRational){1, codec->sample_rate}, + (AVRational){1, 1000000000}); + } + side_data = av_packet_get_side_data(pkt, AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL, &side_data_size); @@ -1323,7 +1334,7 @@ static void mkv_write_block(AVFormatContext *s, AVIOContext *pb, side_data_size -= 8; } - if (side_data_size && additional_id == 1) { + if ((side_data_size && additional_id == 1) || discard_padding) { block_group = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, 0); blockid = MATROSKA_ID_BLOCK; } @@ -1337,6 +1348,10 @@ static void mkv_write_block(AVFormatContext *s, AVIOContext *pb, if (data != pkt->data) av_free(data); + if (discard_padding) { + put_ebml_uint(pb, MATROSKA_ID_DISCARDPADDING, discard_padding); + } + if (side_data_size && additional_id == 1) { block_additions = start_ebml_master(pb, MATROSKA_ID_BLOCKADDITIONS, 0); block_more = start_ebml_master(pb, MATROSKA_ID_BLOCKMORE, 0); @@ -1346,6 +1361,8 @@ static void mkv_write_block(AVFormatContext *s, AVIOContext *pb, avio_write(pb, side_data, side_data_size); end_ebml_master(pb, block_more); end_ebml_master(pb, block_additions); + } + if ((side_data_size && additional_id == 1) || discard_padding) { end_ebml_master(pb, block_group); } } @@ -1562,6 +1579,9 @@ static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt) ret = mkv->cur_audio_pkt.buf ? 0 : AVERROR(ENOMEM); } else ret = av_dup_packet(&mkv->cur_audio_pkt); + if (mkv->cur_audio_pkt.side_data_elems > 0) { + ret = av_copy_packet_side_data(&mkv->cur_audio_pkt, &mkv->cur_audio_pkt); + } } else ret = mkv_write_packet_internal(s, pkt); return ret;