[FFmpeg-devel] [PATCH v4 5/7] avformat/movenc: utilize existing AC-3 parsing workflow for AC-3

["Jan Ekström" <jeebjp@gmail.com>]

From: Jan Ekström <jan.ekstrom@24i.com>

Signed-off-by: Jan Ekström <jan.ekstrom@24i.com>
---
 libavcodec/Makefile           |  1 +
 libavformat/Makefile          |  1 +
 libavformat/ac3_bitrate_tab.c | 22 ++++++++++++++
 libavformat/movenc.c          | 55 +++++++++++++++++------------------
 4 files changed, 51 insertions(+), 28 deletions(-)
 create mode 100644 libavformat/ac3_bitrate_tab.c

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 10697d31f7..7e0d278e3d 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1018,6 +1018,7 @@ STLIBOBJS-$(CONFIG_FLV_MUXER)          += mpeg4audio_sample_rates.o
 STLIBOBJS-$(CONFIG_HLS_DEMUXER)        += ac3_channel_layout_tab.o
 STLIBOBJS-$(CONFIG_MATROSKA_DEMUXER)   += mpeg4audio_sample_rates.o
 STLIBOBJS-$(CONFIG_MOV_DEMUXER)        += ac3_channel_layout_tab.o
+STLIBOBJS-$(CONFIG_MOV_MUXER)          += ac3_bitrate_tab.o
 STLIBOBJS-$(CONFIG_MXF_MUXER)          += golomb.o
 STLIBOBJS-$(CONFIG_MP3_MUXER)          += mpegaudiotabs.o
 STLIBOBJS-$(CONFIG_NUT_MUXER)          += mpegaudiotabs.o
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 1416bf31bd..c71de95b2f 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -699,6 +699,7 @@ SHLIBOBJS-$(CONFIG_FLV_MUXER)            += mpeg4audio_sample_rates.o
 SHLIBOBJS-$(CONFIG_HLS_DEMUXER)          += ac3_channel_layout_tab.o
 SHLIBOBJS-$(CONFIG_MATROSKA_DEMUXER)     += mpeg4audio_sample_rates.o
 SHLIBOBJS-$(CONFIG_MOV_DEMUXER)          += ac3_channel_layout_tab.o
+SHLIBOBJS-$(CONFIG_MOV_MUXER)            += ac3_bitrate_tab.o
 SHLIBOBJS-$(CONFIG_MP3_MUXER)            += mpegaudiotabs.o
 SHLIBOBJS-$(CONFIG_MXF_MUXER)            += golomb_tab.o
 SHLIBOBJS-$(CONFIG_NUT_MUXER)            += mpegaudiotabs.o
diff --git a/libavformat/ac3_bitrate_tab.c b/libavformat/ac3_bitrate_tab.c
new file mode 100644
index 0000000000..57b6181511
--- /dev/null
+++ b/libavformat/ac3_bitrate_tab.c
@@ -0,0 +1,22 @@
+/*
+ * AC-3 bit rate table
+ * copyright (c) 2001 Fabrice Bellard
+ *
+ * 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
+ */
+
+#include "libavcodec/ac3_bitrate_tab.h"
diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 103f958d75..a071f1cdd5 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -36,6 +36,7 @@
 #include "av1.h"
 #include "avc.h"
 #include "libavcodec/ac3_parser_internal.h"
+#include "libavcodec/ac3tab.h"
 #include "libavcodec/dnxhddata.h"
 #include "libavcodec/flac.h"
 #include "libavcodec/get_bits.h"
@@ -362,44 +363,42 @@ struct eac3_info {
 
 static int mov_write_ac3_tag(AVFormatContext *s, AVIOContext *pb, MOVTrack *track)
 {
-    GetBitContext gbc;
+    struct eac3_info *info = track->eac3_priv;
+    int8_t ac3_bit_rate_code = -1;
     PutBitContext pbc;
     uint8_t buf[3];
-    int fscod, bsid, bsmod, acmod, lfeon, frmsizecod;
 
-    if (track->vos_len < 7) {
+    if (!info || !info->ec3_done) {
         av_log(s, AV_LOG_ERROR,
                "Cannot write moov atom before AC3 packets."
                " Set the delay_moov flag to fix this.\n");
         return AVERROR(EINVAL);
     }
 
-    avio_wb32(pb, 11);
-    ffio_wfourcc(pb, "dac3");
+    for (unsigned int i = 0; i < FF_ARRAY_ELEMS(ff_ac3_bitrate_tab); i++) {
+        if (info->data_rate == ff_ac3_bitrate_tab[i]) {
+            ac3_bit_rate_code = i;
+            break;
+        }
+    }
 
-    init_get_bits(&gbc, track->vos_data + 4, (track->vos_len - 4) * 8);
-    fscod      = get_bits(&gbc, 2);
-    frmsizecod = get_bits(&gbc, 6);
-    bsid       = get_bits(&gbc, 5);
-    bsmod      = get_bits(&gbc, 3);
-    acmod      = get_bits(&gbc, 3);
-    if (acmod == 2) {
-        skip_bits(&gbc, 2); // dsurmod
-    } else {
-        if ((acmod & 1) && acmod != 1)
-            skip_bits(&gbc, 2); // cmixlev
-        if (acmod & 4)
-            skip_bits(&gbc, 2); // surmixlev
+    if (ac3_bit_rate_code < 0) {
+        av_log(s, AV_LOG_ERROR,
+               "No valid AC3 bit rate code for data rate of %d!\n",
+               info->data_rate);
+        return AVERROR(EINVAL);
     }
-    lfeon = get_bits1(&gbc);
+
+    avio_wb32(pb, 11);
+    ffio_wfourcc(pb, "dac3");
 
     init_put_bits(&pbc, buf, sizeof(buf));
-    put_bits(&pbc, 2, fscod);
-    put_bits(&pbc, 5, bsid);
-    put_bits(&pbc, 3, bsmod);
-    put_bits(&pbc, 3, acmod);
-    put_bits(&pbc, 1, lfeon);
-    put_bits(&pbc, 5, frmsizecod >> 1); // bit_rate_code
+    put_bits(&pbc, 2, info->substream[0].fscod);
+    put_bits(&pbc, 5, info->substream[0].bsid);
+    put_bits(&pbc, 3, info->substream[0].bsmod);
+    put_bits(&pbc, 3, info->substream[0].acmod);
+    put_bits(&pbc, 1, info->substream[0].lfeon);
+    put_bits(&pbc, 5, ac3_bit_rate_code); // bit_rate_code
     put_bits(&pbc, 5, 0); // reserved
 
     flush_put_bits(&pbc);
@@ -5975,8 +5974,7 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
     if ((par->codec_id == AV_CODEC_ID_DNXHD ||
          par->codec_id == AV_CODEC_ID_H264 ||
          par->codec_id == AV_CODEC_ID_HEVC ||
-         par->codec_id == AV_CODEC_ID_TRUEHD ||
-         par->codec_id == AV_CODEC_ID_AC3) && !trk->vos_len &&
+         par->codec_id == AV_CODEC_ID_TRUEHD) && !trk->vos_len &&
          !TAG_IS_AVCI(trk->tag)) {
         /* copy frame to create needed atoms */
         trk->vos_len  = size;
@@ -6053,7 +6051,8 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
             }
         }
 
-    } else if (par->codec_id == AV_CODEC_ID_EAC3) {
+    } else if (par->codec_id == AV_CODEC_ID_EAC3 ||
+               par->codec_id == AV_CODEC_ID_AC3) {
         size = handle_eac3(mov, pkt, trk);
         if (size < 0)
             return size;
-- 
2.36.1

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