[FFmpeg-devel] [PATCH v4 1/2 ] avformat/mpegts: opus muxing for mapping family 255

[pkv.stream]

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From 105f20b8af8ce5376165ca30a81276dae2e61e40 Mon Sep 17 00:00:00 2001
From: pkviet <pkv.stream at gmail.com>
Date: Sat, 28 Oct 2017 02:48:08 +0200
Subject: [PATCH 1/2] libavf/mpegts: opus muxing for mapping family 255

Adds to mpegts muxer the capability  to mux libopus with mapping family
255, following the provisional spec for opus in mepg-ts
(https://people.xiph.org/~tterribe/opus/ETSI_TS_opus-v0.1.3-draft.doc).

Signed-off-by: pkviet <pkv.stream at gmail.com>
---
 libavformat/mpegtsenc.c | 67 +++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 60 insertions(+), 7 deletions(-)

diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
index fdfa544..a31663c 100644
--- a/libavformat/mpegtsenc.c
+++ b/libavformat/mpegtsenc.c
@@ -28,6 +28,7 @@
 #include "libavutil/opt.h"
 
 #include "libavcodec/internal.h"
+#include "libavcodec/put_bits.h"
 
 #include "avformat.h"
 #include "avio_internal.h"
@@ -291,6 +292,9 @@ static int mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
     MpegTSWrite *ts = s->priv_data;
     uint8_t data[SECTION_LENGTH], *q, *desc_length_ptr, *program_info_length_ptr;
     int val, stream_type, i, err = 0;
+    uint8_t channel_count, stream_count, coupled_stream_count, *buf;
+    PutBitContext pbc;
+    size_t buf_size;
 
     q = data;
     put16(&q, 0xe000 | service->pcr_pid);
@@ -421,8 +425,8 @@ static int mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
                 *q++ = 'D';
             }
             if (st->codecpar->codec_id==AV_CODEC_ID_OPUS) {
-                /* 6 bytes registration descriptor, 4 bytes Opus audio descriptor */
-                if (q - data > SECTION_LENGTH - 6 - 4) {
+                /* 6 bytes registration descriptor, 6 bytes Opus audio descriptor */
+                if (q - data > SECTION_LENGTH - 6 - 6) {
                     err = 1;
                     break;
                 }
@@ -435,8 +439,19 @@ static int mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
                 *q++ = 's';
 
                 *q++ = 0x7f; /* DVB extension descriptor */
-                *q++ = 2;
-                *q++ = 0x80;
+                /* descriptor_length */
+                if (st->codecpar->extradata[18] == 255) {
+                    /* dual mono */
+                    if (st->codecpar->channels == 2) {
+                        *q++ = 2;
+                    } else {
+                    /* channel_config_code 0x81 */
+                        *q++ = st->codecpar->channels + 6;
+                    }
+                } else {
+                    *q++ = 2;
+                }
+                *q++ = 0x80; /* descriptor_tag_extension */
 
                 if (st->codecpar->extradata && st->codecpar->extradata_size >= 19) {
                     if (st->codecpar->extradata[18] == 0 && st->codecpar->channels <= 2) {
@@ -483,9 +498,47 @@ static int mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
                             *q++ = 0xff;
                         }
                     } else {
-                        /* Unsupported */
-                        av_log(s, AV_LOG_ERROR, "Unsupported Opus channel mapping for family %d", st->codecpar->extradata[18]);
-                        *q++ = 0xff;
+                        /* mapping family 255 , set channel_config_code to 0x81 except for dual-mono */
+                        if (st->codecpar->extradata[18] == 255) {
+                            /* dual mono */
+                            if (st->codecpar->channels == 2 && st->codecpar->extradata[19] == 1) {
+                                *q++ = 0x00;
+                            } else if (st->codecpar->channels == 2 && st->codecpar->extradata[19] == 2) {
+                                *q++ = 0x80;
+                            } else {
+                            /* application defined channel configuration */
+                                *q++ = 0x81;
+                                *q++ = st->codecpar->channels;
+                                *q++ = st->codecpar->extradata[18];
+                                channel_count = st->codecpar->channels;
+                                stream_count = st->codecpar->extradata[19];
+                                coupled_stream_count = st->codecpar->extradata[20];
+                                buf = av_mallocz_array( st->codecpar->channels + 2 , sizeof(uint8_t));
+                                if (!buf) {
+                                        av_freep(buf);
+                                        return AVERROR(ENOMEM);
+                                }
+                                init_put_bits(&pbc, buf, (st->codecpar->channels + 2));
+                                put_bits(&pbc, av_ceil_log2_c(channel_count), st->codecpar->extradata[19] - 1);
+                                put_bits(&pbc, av_ceil_log2_c(stream_count + 1), st->codecpar->extradata[20]);
+                                for (i = 0; i < channel_count; i++) {
+                                    put_bits(&pbc, av_ceil_log2_c(stream_count + coupled_stream_count + 1), st->codecpar->extradata[21 + i]);
+                                }
+                                flush_put_bits(&pbc);
+                                buf_size = av_ceil_log2_c(channel_count) + av_ceil_log2_c(stream_count + 1)
+                                       + channel_count * (av_ceil_log2_c(stream_count + coupled_stream_count + 1))
+                                       + (8 * (2 + channel_count) - av_ceil_log2_c(channel_count) - av_ceil_log2_c(stream_count + 1)
+                                       - channel_count * (av_ceil_log2_c(stream_count + coupled_stream_count + 1))) % 8;
+                                for (i = 0; i < buf_size; i++) {
+                                    memcpy(q++, buf+i, 1);
+                                }
+                                av_freep(&buf);
+                            }
+                        } else {
+                            /* Unsupported */
+                            av_log(s, AV_LOG_ERROR, "Unsupported Opus channel mapping for family %d", st->codecpar->extradata[18]);
+                            *q++ = 0xff;
+                        }
                     }
                 } else if (st->codecpar->channels <= 2) {
                     /* Assume RTP mapping family */
-- 
2.10.1.windows.1