FFMPEG successfully reverse engineered RV30/RV40!

Question

FFMPEG's GSoC project to reverse engineer RealMedia's RV30 and RV40 codecs has been successful. It looks like there is still work to do, but it's a reality now:
http://lists.mplayerhq.hu/pipermail/ffm … 35486.html
They are also finishing other needed stuff like their Monkey Audio decoder, Matroska muxer, support for RTSP, RTP, MMS, and other streams, and much more.
It looks as if the dream of Linux being able to play just about anything with native, open source code is coming to fruition. On top of that, FFMPEG has matured before MPlayer or VLC has had to start their inevitable legal battles that have been brewing for years. After all, FFMPEG was started because MPlayer's future was looking pretty grim.
This is indeed a very good thing for all of the *nix family.

Answer 1

Current SVN still doesn't have the changes I posted. But, this is a modified ffmpeg.patch file that will give rudimentary eac3 support to a very current (today works) SVN version of FFMPEG. The subversion repo to pull it and all the eac3 stuff down from is:
http://svn.mplayerhq.hu/soc/eac3/
So, to drop the files into the directory eac3 in the current directory:
svn checkout svn://svn.mplayerhq.hu/soc/eac3 eac3
All the C source and header files need to be dropped into libavcodec from FFMPEG:
svn checkout svn://svn.mplayerhq.hu/ffmpeg/trunk ffmpeg
The modified patch. This replaces ffmpeg.patch from the eac3 directory:
Index: libavcodec/ac3_parser.c
===================================================================
--- libavcodec/ac3_parser.c (wersja 10220)
+++ libavcodec/ac3_parser.c (kopia robocza)
@@ -84,7 +84,7 @@
return 0;
-static int ac3_sync(const uint8_t *buf, int *channels, int *sample_rate,
+static int ac3_sync(AVCodecContext *avctx, const uint8_t *buf, int *channels, int *sample_rate,
int *bit_rate, int *samples)
int err;
@@ -100,12 +100,16 @@
bsid = hdr.bsid;
if(bsid <= 10) { /* Normal AC-3 */
+ if(avctx->codec_id == CODEC_ID_EAC3)
+ avctx->codec_id = CODEC_ID_AC3;
*sample_rate = hdr.sample_rate;
*bit_rate = hdr.bit_rate;
*channels = hdr.channels;
*samples = AC3_FRAME_SIZE;
return hdr.frame_size;
} else if (bsid > 10 && bsid <= 16) { /* Enhanced AC-3 */
+ if(avctx->codec_id == CODEC_ID_AC3)
+ avctx->codec_id = CODEC_ID_EAC3;
init_get_bits(&bits, &buf[2], (AC3_HEADER_SIZE-2) * 8);
strmtyp = get_bits(&bits, 2);
substreamid = get_bits(&bits, 3);
@@ -152,6 +156,13 @@
return 0;
+AVCodecParser eac3_parser = {
+ { CODEC_ID_EAC3 },
+ sizeof(AACAC3ParseContext),
+ ac3_parse_init,
+ ff_aac_ac3_parse,
+ NULL,
+};
AVCodecParser ac3_parser = {
{ CODEC_ID_AC3 },
Index: libavcodec/Makefile
===================================================================
--- libavcodec/Makefile (wersja 10220)
+++ libavcodec/Makefile (kopia robocza)
@@ -64,6 +64,7 @@
OBJS-$(CONFIG_DVVIDEO_DECODER) += dv.o
OBJS-$(CONFIG_DVVIDEO_ENCODER) += dv.o
OBJS-$(CONFIG_DXA_DECODER) += dxa.o
+OBJS-$(CONFIG_EAC3_DECODER) += eac3dec.o ac3dec.o
OBJS-$(CONFIG_EIGHTBPS_DECODER) += 8bps.o
OBJS-$(CONFIG_FFV1_DECODER) += ffv1.o rangecoder.o golomb.o
OBJS-$(CONFIG_FFV1_ENCODER) += ffv1.o rangecoder.o
Index: libavcodec/aac_ac3_parser.c
===================================================================
--- libavcodec/aac_ac3_parser.c (wersja 10220)
+++ libavcodec/aac_ac3_parser.c (kopia robocza)
@@ -48,7 +48,7 @@
s->inbuf_ptr += len;
buf_size -= len;
if ((s->inbuf_ptr - s->inbuf) == s->header_size) {
- len = s->sync(s->inbuf, &channels, &sample_rate, &bit_rate,
+ len = s->sync(avctx, s->inbuf, &channels, &sample_rate, &bit_rate,
&samples);
if (len == 0) {
/* no sync found : move by one byte (inefficient, but simple!) */
@@ -59,7 +59,7 @@
/* update codec info */
avctx->sample_rate = sample_rate;
/* set channels,except if the user explicitly requests 1 or 2 channels, XXX/FIXME this is a bit ugly */
- if(avctx->codec_id == CODEC_ID_AC3){
+ if(avctx->codec_id == CODEC_ID_AC3 || avctx->codec_id == CODEC_ID_EAC3){
if(avctx->channels!=1 && avctx->channels!=2){
avctx->channels = channels;
Index: libavcodec/aac_ac3_parser.h
===================================================================
--- libavcodec/aac_ac3_parser.h (wersja 10220)
+++ libavcodec/aac_ac3_parser.h (kopia robocza)
@@ -30,7 +30,7 @@
uint8_t *inbuf_ptr;
int frame_size;
int header_size;
- int (*sync)(const uint8_t *buf, int *channels, int *sample_rate,
+ int (*sync)(AVCodecContext *avctx, const uint8_t *buf, int *channels, int *sample_rate,
int *bit_rate, int *samples);
uint8_t inbuf[8192]; /* input buffer */
} AACAC3ParseContext;
Index: libavcodec/aac_parser.c
===================================================================
--- libavcodec/aac_parser.c (wersja 10220)
+++ libavcodec/aac_parser.c (kopia robocza)
@@ -38,7 +38,7 @@
-static int aac_sync(const uint8_t *buf, int *channels, int *sample_rate,
+static int aac_sync(AVCodecContext *avctx, const uint8_t *buf, int *channels, int *sample_rate,
int *bit_rate, int *samples)
GetBitContext bits;
Index: libavcodec/allcodecs.c
===================================================================
--- libavcodec/allcodecs.c (wersja 10220)
+++ libavcodec/allcodecs.c (kopia robocza)
@@ -178,6 +178,7 @@
REGISTER_DECODER (COOK, cook);
REGISTER_DECODER (DCA, dca);
REGISTER_DECODER (DSICINAUDIO, dsicinaudio);
+ REGISTER_DECODER (EAC3, eac3);
REGISTER_ENCDEC (FLAC, flac);
REGISTER_DECODER (IMC, imc);
REGISTER_ENCDEC (LIBAMR_NB, libamr_nb);
@@ -272,6 +272,7 @@
REGISTER_PARSER (DCA, dca);
REGISTER_PARSER (DVBSUB, dvbsub);
REGISTER_PARSER (DVDSUB, dvdsub);
+ REGISTER_PARSER (EAC3, eac3);
REGISTER_PARSER (H261, h261);
REGISTER_PARSER (H263, h263);
REGISTER_PARSER (H264, h264);
Index: libavcodec/avcodec.h
===================================================================
--- libavcodec/avcodec.h (wersja 10220)
+++ libavcodec/avcodec.h (kopia robocza)
@@ -261,6 +261,7 @@
CODEC_ID_GSM_MS, /* as found in WAV */
CODEC_ID_ATRAC3,
CODEC_ID_VOXWARE,
CODEC_ID_APE,
+ CODEC_ID_EAC3,
/* subtitle codecs */
CODEC_ID_DVD_SUBTITLE= 0x17000,
Index: libavcodec/allcodecs.h
===================================================================
--- libavcodec/ac3enc.c (wersja 10220)
+++ libavcodec/ac3enc.c (kopia robocza)
@@ -479,7 +479,8 @@
for(ch=0;ch<s->nb_all_channels;ch++) {
ff_ac3_bit_alloc_calc_bap(mask[i][ch], psd[i][ch], 0,
s->nb_coefs[ch], snroffset,
- s->bit_alloc.floor, bap[i][ch]);
+ s->bit_alloc.floor, ff_ac3_baptab,
+ bap[i][ch]);
frame_bits += compute_mantissa_size(s, bap[i][ch],
s->nb_coefs[ch]);
Index: ffmpeg.c
===================================================================
--- ffmpeg.c (wersja 10220)
+++ ffmpeg.c (kopia robocza)
@@ -1577,6 +1577,7 @@
} else {
if (codec->channels != icodec->channels &&
(icodec->codec_id == CODEC_ID_AC3 ||
+ icodec->codec_id == CODEC_ID_EAC3 ||
icodec->codec_id == CODEC_ID_DTS)) {
/* Special case for 5:1 AC3 and DTS input */
/* and mono or stereo output */
I'm not going to post a PKGBUILD for this. It's too much work for something that doesn't really function yet. I mean, the .evo test file from MPlayer works basically, but both the video and audio are choppy. The other test file I picked up doesn't work at all.
Oh yeah, if anyone cares, this is part of the output from FFMPEG:
Input #0, mpeg, from 'MAININTRO.EVO':
Duration: 00:01:04.2, start: 0.038278, bitrate: 17089 kb/s
Stream #0.0[0xfd55]: Video: vc1, yuv420p, 1920x1080, 29.97 fps(r)
Stream #0.1[0xc0]: Audio: E-AC3, 48000 Hz, 5:1, 768 kb/s
---------------------- I did tell one lie (at least) -----------------------
I was able to play a MonkeyAudio (.ape) file with FFPlay. That's new!
Last edited by skottish (2007-09-26 04:46:39)