[FFmpeg-devel] [PATCH] Lego Mindstorms RSO de/muxer (copied from au.c)
Rafaël Carré
rafael.carre
Wed Jul 14 21:54:31 CEST 2010
- format from http://bricxcc.sourceforge.net/
- TODO: IMA ADPCM, it seems to be the CODEC_ID_ADPCM_IMA_WAV codec, but
predictor/step are not passed in the bitstream.
I sent a sample to Kostya, if he finds the (fixed for RSO) parameters,
we could put them in extradata and check if extradata is present in
the decoder.
- Totally untested on reference implementation (i didn't have/play Lego
for years), but demuxing/remuxing gives the same output
- Since the header is very simple and has no magic:
16be codec id (PCM U8 / ADPCM)
16be file size
16be sample rate
16be play mode (loop)
I have no idea for a probing function so demuxing has to be forced
with -f rso
Note: file size is limited to 65535 bytes + 8 bytes header (output is
stored on a ~128kB flash, probably together with code)
---
Changelog | 1 +
libavformat/Makefile | 2 +
libavformat/allformats.c | 1 +
libavformat/rso.c | 203 ++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 207 insertions(+), 0 deletions(-)
create mode 100644 libavformat/rso.c
diff --git a/Changelog b/Changelog
index 6a04869..d408942 100644
--- a/Changelog
+++ b/Changelog
@@ -21,6 +21,7 @@ version <next>:
- ffplay -exitonkeydown and -exitonmousedown options added
- native GSM / GSM MS decoder
- RTP depacketization of QDM2
+- Lego Mindstorms RSO de/muxer
diff --git a/libavformat/Makefile b/libavformat/Makefile
index cab222c..dc5ef8e 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -209,6 +209,8 @@ OBJS-$(CONFIG_RM_DEMUXER) += rmdec.o rm.o
OBJS-$(CONFIG_RM_MUXER) += rmenc.o rm.o
OBJS-$(CONFIG_ROQ_DEMUXER) += idroq.o
OBJS-$(CONFIG_ROQ_MUXER) += raw.o
+OBJS-$(CONFIG_RSO_DEMUXER) += rso.o raw.o
+OBJS-$(CONFIG_RSO_MUXER) += rso.o
OBJS-$(CONFIG_RPL_DEMUXER) += rpl.o
OBJS-$(CONFIG_RTP_MUXER) += rtp.o \
rtpenc_aac.o \
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 94ab78c..66aab6e 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -174,6 +174,7 @@ void av_register_all(void)
REGISTER_MUXDEMUX (RM, rm);
REGISTER_MUXDEMUX (ROQ, roq);
REGISTER_DEMUXER (RPL, rpl);
+ REGISTER_MUXDEMUX (RSO, rso);
REGISTER_MUXER (RTP, rtp);
REGISTER_MUXDEMUX (RTSP, rtsp);
REGISTER_DEMUXER (SDP, sdp);
diff --git a/libavformat/rso.c b/libavformat/rso.c
new file mode 100644
index 0000000..3af132d
--- /dev/null
+++ b/libavformat/rso.c
@@ -0,0 +1,203 @@
+/*
+ * RSO muxer and demuxer
+ * Copyright (c) 2001 Fabrice Bellard (original AU code)
+ * Copyright ?? 2010 Rafa??l Carr??
+ *
+ * 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 "avformat.h"
+#include "raw.h"
+#include "riff.h"
+
+#define RSO_HEADER_SIZE 8
+
+/* The ffmpeg codecs we support, and the IDs they have in the file */
+static const AVCodecTag codec_rso_tags[] = {
+ { CODEC_ID_PCM_U8, 0x0100 },
+ { CODEC_ID_ADPCM_IMA_WAV, 0x0101 },
+ { CODEC_ID_NONE, 0 },
+};
+
+#if CONFIG_RSO_MUXER
+static int rso_write_header(AVFormatContext *s)
+{
+ ByteIOContext *pb = s->pb;
+ AVCodecContext *enc = s->streams[0]->codec;
+
+ if (!enc->codec_tag)
+ return -1;
+
+ if (enc->channels != 1) {
+ av_log(s, AV_LOG_ERROR, "RSO only supports mono\n");
+ return -1;
+ }
+
+ if (url_is_streamed(s->pb)) {
+ av_log(s, AV_LOG_ERROR, "muxer does not support non seekable output\n");
+ return -1;
+ }
+
+ if (enc->sample_rate >= 1u<<16) {
+ av_log(s, AV_LOG_ERROR, "Sample rate must be < 65536\n");
+ return -1;
+ }
+
+ if (enc->codec_id == CODEC_ID_ADPCM_IMA_WAV) {
+ av_log(s, AV_LOG_ERROR, "ADPCM in RSO not implemented\n");
+ return -1;
+ }
+
+ s->priv_data = NULL;
+
+ /* format header */
+ put_be16(pb, enc->codec_tag); /* codec ID */
+ put_be16(pb, 0); /* data size, will be written at EOF */
+ put_be16(pb, enc->sample_rate);
+ put_be16(pb, 0x0000); /* play mode ? (0x0000 = don't loop) */
+
+ put_flush_packet(pb);
+
+ return 0;
+}
+
+static int rso_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+ put_buffer(s->pb, pkt->data, pkt->size);
+ return 0;
+}
+
+static int rso_write_trailer(AVFormatContext *s)
+{
+ ByteIOContext *pb = s->pb;
+ int64_t file_size;
+ int16_t coded_file_size;
+
+ file_size = url_ftell(pb);
+
+ if (file_size < 0)
+ return file_size;
+
+ if (file_size > 0xffff + RSO_HEADER_SIZE) {
+ av_log(s, AV_LOG_WARNING,
+ "Output file is too big (%"PRId64" bytes >= 64kB)\n",
+ file_size);
+ coded_file_size = 0xffff;
+ } else {
+ coded_file_size = file_size - RSO_HEADER_SIZE;
+ }
+
+ /* update file size */
+ url_fseek(pb, 2, SEEK_SET);
+ put_be16(pb, coded_file_size);
+ url_fseek(pb, file_size, SEEK_SET);
+
+ put_flush_packet(pb);
+
+ return 0;
+}
+#endif /* CONFIG_RSO_MUXER */
+
+#if CONFIG_RSO_DEMUXER
+static int rso_read_header(AVFormatContext *s, AVFormatParameters *ap)
+{
+ ByteIOContext *pb = s->pb;
+ unsigned int id, rate, size, bpp;
+ enum CodecID codec;
+ AVStream *st;
+
+ id = get_be16(pb);
+ size = get_be16(pb);
+ rate = get_be16(pb);
+
+ get_be16(pb); /* play mode ? (0x0000 = don't loop) */
+
+ codec = ff_codec_get_id(codec_rso_tags, id);
+
+ if (codec == CODEC_ID_ADPCM_IMA_WAV) {
+ av_log(s, AV_LOG_ERROR, "ADPCM in RSO not implemented\n");
+ return -1;
+ }
+
+ bpp = av_get_bits_per_sample(codec);
+ if (!bpp) {
+ av_log_ask_for_sample(s, "could not determine bits per sample\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ /* now we are ready: build format streams */
+ st = av_new_stream(s, 0);
+ if (!st)
+ return -1;
+ st->duration = size << 3 / bpp;
+ st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
+ st->codec->codec_tag = id;
+ st->codec->codec_id = codec;
+ st->codec->channels = 1;
+ st->codec->sample_rate = rate;
+ av_set_pts_info(st, 64, 1, rate);
+ return 0;
+}
+
+#define BLOCK_SIZE 1024
+
+static int rso_read_packet(AVFormatContext *s,
+ AVPacket *pkt)
+{
+ int ret;
+ int bpp = av_get_bits_per_sample(s->streams[0]->codec->codec_id);
+
+ ret= av_get_packet(s->pb, pkt, BLOCK_SIZE * bpp >> 3);
+ if (ret < 0)
+ return ret;
+ pkt->stream_index = 0;
+
+ /* note: we need to modify the packet size here to handle the last
+ packet */
+ pkt->size = ret;
+ return 0;
+}
+#endif /* CONFIG_RSO_DEMUXER */
+
+#if CONFIG_RSO_DEMUXER
+AVInputFormat rso_demuxer = {
+ .name = "rso",
+ .long_name = NULL_IF_CONFIG_SMALL("Lego Mindstorms RSO format"),
+ .priv_data_size = 0,
+ .read_probe = NULL,
+ .read_header = rso_read_header,
+ .read_packet = rso_read_packet,
+ .read_close = NULL,
+ .read_seek = pcm_read_seek,
+ .codec_tag = (const AVCodecTag* const []){codec_rso_tags, 0},
+};
+#endif
+
+#if CONFIG_RSO_MUXER
+AVOutputFormat rso_muxer = {
+ .name = "rso",
+ .long_name = NULL_IF_CONFIG_SMALL("Lego Mindstorms RSO format"),
+ .extensions = "rso",
+ .priv_data_size = 0,
+ .audio_codec = CODEC_ID_PCM_U8,
+ .video_codec = CODEC_ID_NONE,
+ .write_header = rso_write_header,
+ .write_packet = rso_write_packet,
+ .write_trailer = rso_write_trailer,
+ .codec_tag = (const AVCodecTag* const []){codec_rso_tags, 0},
+};
+#endif
--
1.7.0.4
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