[FFmpeg-devel] [PATCH] avformat/oggenc: Add partial support for OggPCM muxing

[A G]

>From 81cf2038424e483e60ed9747f965ec452d357773 Mon Sep 17 00:00:00 2001
From: oreo639 <31916379+Oreo639 at users.noreply.github.com>
Date: Wed, 27 May 2020 17:18:03 -0700
Subject: [PATCH] avformat/oggenc: Add partial support for OggPCM muxing

This adds partial support for OggPCM demuxing.
Heavily based on the work here:
https://ffmpeg.org/pipermail/ffmpeg-devel/2013-July/145556.html
and here:
http://www.on2.com/media/gpl/mplayer/

---
 libavformat/oggenc.c | 85 ++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 79 insertions(+), 6 deletions(-)

diff --git a/libavformat/oggenc.c b/libavformat/oggenc.c
index f5032759a6..5f03b4d9b7 100644
--- a/libavformat/oggenc.c
+++ b/libavformat/oggenc.c
@@ -99,6 +99,36 @@ static const AVClass flavor ## _muxer_class = {\
     .version    = LIBAVUTIL_VERSION_INT,\
 };

+
+static const struct ogg_pcm_codec {
+    uint32_t codec_id;
+    uint32_t format_id;
+} ogg_pcm_codecs[] = {
+    { AV_CODEC_ID_PCM_S8,    0x00 },
+    { AV_CODEC_ID_PCM_U8,    0x01 },
+    { AV_CODEC_ID_PCM_S16LE, 0x02 },
+    { AV_CODEC_ID_PCM_S16BE, 0x03 },
+    { AV_CODEC_ID_PCM_S24LE, 0x04 },
+    { AV_CODEC_ID_PCM_S24BE, 0x05 },
+    { AV_CODEC_ID_PCM_S32LE, 0x06 },
+    { AV_CODEC_ID_PCM_S32BE, 0x07 },
+    { AV_CODEC_ID_PCM_F32LE, 0x20 },
+    { AV_CODEC_ID_PCM_F32BE, 0x21 },
+    { AV_CODEC_ID_PCM_F64LE, 0x22 },
+    { AV_CODEC_ID_PCM_F64BE, 0x23 },
+};
+
+static inline uint32_t ogg_get_pcm_format_id(uint32_t codec_id)
+{
+    int i;
+
+    for (i = 0; i < FF_ARRAY_ELEMS(ogg_pcm_codecs); i++)
+        if (ogg_pcm_codecs[i].codec_id == codec_id)
+            return ogg_pcm_codecs[i].format_id;
+
+    return 0;
+}
+
 static void ogg_write_page(AVFormatContext *s, OGGPage *page, int extra_flags)
 {
     OGGStreamContext *oggstream = s->streams[page->stream_index]->priv_data;
@@ -363,6 +393,39 @@ static int ogg_build_speex_headers(AVCodecParameters *par,
     return 0;
 }

+#define OGGPCM_HEADER_SIZE 224
+
+static int ogg_build_pcm_headers(AVCodecParameters *par,
+                                   OGGStreamContext *oggstream, int bitexact,
+                                   AVDictionary **m)
+{
+    uint8_t *p;
+
+    // first packet: OggPCM header
+    p = av_mallocz(OGGPCM_HEADER_SIZE);
+    if (!p)
+        return AVERROR(ENOMEM);
+    oggstream->header[0] = p;
+    oggstream->header_len[0] = OGGPCM_HEADER_SIZE;
+    bytestream_put_buffer(&p, "PCM     ", 8); // Identifier
+    bytestream_put_be16(&p, 0x00); // VMAJ
+    bytestream_put_be16(&p, 0x00); // VMIN
+    bytestream_put_be32(&p, ogg_get_pcm_format_id(par->codec_id)); // PCM fmt
+    bytestream_put_be32(&p, par->sample_rate); // Sample rate
+    bytestream_put_byte(&p, 0); // Significant bits (0 == Same as fmt)
+    bytestream_put_byte(&p, par->channels); // Channels
+    bytestream_put_be16(&p, 0); // Max frames per packet TODO:// Actually calculate max frames per packet
+    bytestream_put_be32(&p, 0); // Number of extra headers
+
+    // second packet: VorbisComment
+    p = ogg_write_vorbiscomment(0, bitexact, &oggstream->header_len[1], m, 0, NULL, 0);
+    if (!p)
+        return AVERROR(ENOMEM);
+    oggstream->header[1] = p;
+
+    return 0;
+}
+
 #define OPUS_HEADER_SIZE 19

 static int ogg_build_opus_headers(AVCodecParameters *par,
@@ -487,18 +550,20 @@ static int ogg_init(AVFormatContext *s)
                 avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
         }

-        if (st->codecpar->codec_id != AV_CODEC_ID_VORBIS &&
-            st->codecpar->codec_id != AV_CODEC_ID_THEORA &&
-            st->codecpar->codec_id != AV_CODEC_ID_SPEEX  &&
-            st->codecpar->codec_id != AV_CODEC_ID_FLAC   &&
-            st->codecpar->codec_id != AV_CODEC_ID_OPUS   &&
+        if (st->codecpar->codec_id != AV_CODEC_ID_VORBIS   &&
+            st->codecpar->codec_id != AV_CODEC_ID_THEORA   &&
+            st->codecpar->codec_id != AV_CODEC_ID_SPEEX    &&
+            st->codecpar->codec_id != AV_CODEC_ID_FLAC     &&
+            st->codecpar->codec_id != AV_CODEC_ID_OPUS     &&
+            !ogg_get_pcm_format_id(st->codecpar->codec_id) &&
             st->codecpar->codec_id != AV_CODEC_ID_VP8) {
             av_log(s, AV_LOG_ERROR, "Unsupported codec id in stream %d\n", i);
             return AVERROR(EINVAL);
         }

         if ((!st->codecpar->extradata || !st->codecpar->extradata_size) &&
-            st->codecpar->codec_id != AV_CODEC_ID_VP8) {
+            st->codecpar->codec_id != AV_CODEC_ID_VP8  &&
+            !ogg_get_pcm_format_id(st->codecpar->codec_id)) {
             av_log(s, AV_LOG_ERROR, "No extradata present\n");
             return AVERROR_INVALIDDATA;
         }
@@ -553,6 +618,14 @@ static int ogg_init(AVFormatContext *s)
                 av_log(s, AV_LOG_ERROR, "Error writing VP8 headers\n");
                 return err;
             }
+        } else if (ogg_get_pcm_format_id(st->codecpar->codec_id)) {
+            int err = ogg_build_pcm_headers(st->codecpar, oggstream,
+                                              s->flags & AVFMT_FLAG_BITEXACT,
+                                              &st->metadata);
+            if (err) {
+                av_log(s, AV_LOG_ERROR, "Error writing OggPCM headers\n");
+                return err;
+            }
         } else {
             uint8_t *p;
             const char *cstr = st->codecpar->codec_id == AV_CODEC_ID_VORBIS ? "vorbis" : "theora";
--
2.26.2