Paul B Mahol:
> Signed-off-by: Paul B Mahol <one...@gmail.com>
> ---
> libavformat/Makefile | 1 +
> libavformat/allformats.c | 1 +
> libavformat/moflex.c | 351 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 353 insertions(+)
> create mode 100644 libavformat/moflex.c
>
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index cbb33fe37c..1e0ac317e5 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -319,6 +319,7 @@ OBJS-$(CONFIG_MLV_DEMUXER) += mlvdec.o
> riffdec.o
> OBJS-$(CONFIG_MM_DEMUXER) += mm.o
> OBJS-$(CONFIG_MMF_DEMUXER) += mmf.o
> OBJS-$(CONFIG_MMF_MUXER) += mmf.o rawenc.o
> +OBJS-$(CONFIG_MOFLEX_DEMUXER) += moflex.o
> OBJS-$(CONFIG_MOV_DEMUXER) += mov.o mov_chan.o mov_esds.o
> replaygain.o
> OBJS-$(CONFIG_MOV_MUXER) += movenc.o av1.o avc.o hevc.o
> vpcc.o \
> movenchint.o mov_chan.o rtp.o \
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index 0aa9dd7198..28331facb9 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -249,6 +249,7 @@ extern AVInputFormat ff_mlv_demuxer;
> extern AVInputFormat ff_mm_demuxer;
> extern AVInputFormat ff_mmf_demuxer;
> extern AVOutputFormat ff_mmf_muxer;
> +extern AVInputFormat ff_moflex_demuxer;
> extern AVInputFormat ff_mov_demuxer;
> extern AVOutputFormat ff_mov_muxer;
> extern AVOutputFormat ff_mp2_muxer;
> diff --git a/libavformat/moflex.c b/libavformat/moflex.c
> new file mode 100644
> index 0000000000..b9696edd4e
> --- /dev/null
> +++ b/libavformat/moflex.c
> @@ -0,0 +1,351 @@
> +/*
> + * MOFLEX demuxer
> + * Copyright (c) 2020 Paul B Mahol
> + *
> + * 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/bytestream.h"
> +
> +#include "avformat.h"
> +#include "internal.h"
> +
> +typedef struct BitReader {
> + unsigned last;
> + unsigned pos;
> +} BitReader;
> +
> +typedef struct MOFLEXDemuxContext {
> + unsigned size;
> + int64_t pos;
> + int64_t ts;
> + int flags;
> + int in_block;
> +
> + BitReader br;
> +} MOFLEXDemuxContext;
> +
> +static int pop(BitReader *br, AVIOContext *pb)
> +{
> + if (avio_feof(pb))
> + return AVERROR_EOF;
> +
> + if ((br->pos & 7) == 0)
> + br->last = (unsigned)avio_r8(pb) << 24U;
> + else
> + br->last <<= 1;
> +
> + br->pos++;
> + return !!(br->last & 0x80000000);
> +}
> +
> +static int pop_int(BitReader *br, AVIOContext *pb, int n)
> +{
> + int value = 0;
> +
> + for (int i = 0; i < n; i++) {
> + int ret = pop(br, pb);
> +
> + if (ret < 0)
> + return ret;
> + value = 2 * value + ret;
> + }
> +
> + return value;
> +}
> +
> +static int pop_length(BitReader *br, AVIOContext *pb)
> +{
> + int ret, n = 1;
> +
> + while ((ret = pop(br, pb)) == 0)
> + n++;
> +
> + if (ret < 0)
> + return ret;
> + return n;
> +}
> +
> +static int read_var_byte(AVFormatContext *s, unsigned *out)
> +{
> + AVIOContext *pb = s->pb;
> + unsigned value = 0, data;
> +
> + data = avio_r8(pb);
> + if (!(data & 0x80)) {
> + *out = data;
> + return 0;
> + }
> +
> + value = (data & 0x7F) << 7;
> + data = avio_r8(pb);
> + if (!(data & 0x80)) {
> + value |= data;
> + *out = value;
> + return 0;
> + }
> +
> + value = ((data & 0x7F) | value) << 7;
> + data = avio_r8(pb);
> + if (!(data & 0x80)) {
> + value |= data;
> + *out = value;
> + return 0;
> + }
> +
> + value = (((data & 0x7F) | value) << 7) | avio_r8(pb);
> + *out = value;
> +
> + return 0;
> +}
> +
> +static int moflex_probe(const AVProbeData *p)
> +{
> + GetByteContext gb;
> + int score = 0;
> +
> + bytestream2_init(&gb, p->buf, p->buf_size);
> +
> + if (bytestream2_get_be16(&gb) != 0x4C32)
> + return 0;
> + score += 10;
> +
> + bytestream2_skip(&gb, 10);
> + if (bytestream2_get_be16(&gb) == 0)
> + return 0;
> + score += 5;
> +
> + while (bytestream2_get_bytes_left(&gb) > 0) {
> + int type = bytestream2_get_byte(&gb);
> + int size = bytestream2_get_byte(&gb);
> +
> + if (type == 0) {
> + score += 5 * (size == 0);
> + break;
> + }
> + if ((type == 1 && size == 12) ||
> + (type == 2 && size == 6) ||
> + (type == 3 && size == 13) ||
> + (type == 4 && size == 2))
> + score += 20;
> + bytestream2_skip(&gb, size);
> + }
> +
> + return FFMIN(AVPROBE_SCORE_MAX, score);
> +}
> +
> +static int moflex_read_sync(AVFormatContext *s)
> +{
> + MOFLEXDemuxContext *m = s->priv_data;
> + AVIOContext *pb = s->pb;
> + unsigned v10;
> +
> + if (avio_rb16(pb) != 0x4C32) {
> + avio_seek(pb, -2, SEEK_CUR);
> + return 1;
> + }
> +
> + v10 = avio_rb16(pb);
> + m->ts = avio_rb64(pb);
> + m->size = avio_rb16(pb) + 1;
> +
> + while (!avio_feof(pb)) {
> + unsigned type, ssize, codec_id = 0;
> + unsigned codec_type, width = 0, height = 0, sample_rate = 0,
> channels = 0;
> + int stream_index = -1;
> + int format;
> + AVRational fps;
> +
> + read_var_byte(s, &type);
> + read_var_byte(s, &ssize);
> +
> + switch (type) {
> + case 0:
> + if (ssize > 0)
> + avio_skip(pb, ssize);
> + return 0;
> + case 2:
> + codec_type = AVMEDIA_TYPE_AUDIO;
> + stream_index = avio_r8(pb);
> + codec_id = avio_r8(pb);
> + switch (codec_id) {
> + case 0: codec_id = AV_CODEC_ID_FASTAUDIO; break;
> + case 1: codec_id = AV_CODEC_ID_ADPCM_IMA_MOFLEX; break;
> + }
> + sample_rate = avio_rb24(pb) + 1;
> + channels = avio_r8(pb) + 1;
> + break;
> + case 1:
> + case 3:
> + codec_type = AVMEDIA_TYPE_VIDEO;
> + stream_index = avio_r8(pb);
> + codec_id = avio_r8(pb);
> + switch (codec_id) {
> + case 0: codec_id = AV_CODEC_ID_MOBICLIP; break;
> + }
> + fps.num = avio_rb16(pb);
> + fps.den = avio_rb16(pb);
> + width = avio_rb16(pb);
> + height = avio_rb16(pb);
> + format = AV_PIX_FMT_YUV420P;
> + avio_skip(pb, type == 3 ? 3 : 2);
> + break;
> + case 4:
> + codec_type = AVMEDIA_TYPE_DATA;
> + stream_index = avio_r8(pb);
> + avio_skip(pb, 1);
> + break;
> + }
> +
> + if (stream_index == s->nb_streams) {
> + AVStream *st = avformat_new_stream(s, NULL);
> +
> + if (!st)
> + return AVERROR(ENOMEM);
> +
> + st->codecpar->codec_type = codec_type;
> + st->codecpar->codec_id = codec_id;
> + st->codecpar->width = width;
> + st->codecpar->height = height;
> + st->codecpar->sample_rate= sample_rate;
> + st->codecpar->channels = channels;
> + st->codecpar->format = format;
> + st->priv_data = av_packet_alloc();
> + if (!st->priv_data)
> + return AVERROR(ENOMEM);
> +
> + if (sample_rate)
> + avpriv_set_pts_info(st, 63, 1, sample_rate);
> + else
> + avpriv_set_pts_info(st, 63, fps.den, fps.num);
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int moflex_read_header(AVFormatContext *s)
> +{
> + int ret;
> +
> + ret = moflex_read_sync(s);
> + if (ret < 0)
> + return ret;
> +
> + s->ctx_flags |= AVFMTCTX_NOHEADER;
When I mentioned the possibility of new streams being created after
read_header, I expected you to say that this would only happen on
invalid streams. Well, never mind. But there is still a problem here: If
allocating the packet fails when creating a new stream after
read_header, the caller is allowed to call av_read_frame() again after
having received an error. And in this case your context contains a
stream without priv_data.
> + avio_seek(s->pb, 0, SEEK_SET);
> +
> + return 0;
> +}
> +
> +static int moflex_read_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> + MOFLEXDemuxContext *m = s->priv_data;
> + AVIOContext *pb = s->pb;
> + BitReader *br = &m->br;
> + int ret;
> +
> + while (!avio_feof(pb)) {
> + if (!m->in_block) {
> + m->pos = avio_tell(pb);
> +
> + ret = moflex_read_sync(s);
> + if (ret < 0)
> + return ret;
> +
> + m->flags = avio_r8(pb);
> + if (m->flags & 2)
> + avio_skip(pb, 2);
> + }
> +
> + while ((avio_tell(pb) < m->pos + m->size) && !avio_feof(pb) &&
> avio_r8(pb)) {
> + int stream_index, bits, pkt_size, endframe;
> + AVPacket *packet;
> +
> + m->in_block = 1;
> +
> + avio_seek(pb, -1, SEEK_CUR);
> + br->pos = br->last = 0;
> +
> + bits = pop_length(br, pb);
> + if (bits < 0)
> + return bits;
> + stream_index = pop_int(br, pb, bits);
> + if (stream_index < 0)
> + return stream_index;
> + if (stream_index >= s->nb_streams)
> + return AVERROR_INVALIDDATA;
> +
> + endframe = pop(br, pb);
> + if (endframe < 0)
> + return endframe;
> + if (endframe) {
> + bits = pop_length(br, pb);
> + if (bits < 0)
> + return bits;
> + pop_int(br, pb, bits);
> + pop(br, pb);
> + bits = pop_length(br, pb);
> + if (bits < 0)
> + return bits;
> + pop_int(br, pb, bits * 2 + 26);
> + }
> +
> + pkt_size = pop_int(br, pb, 13) + 1;
> + packet = s->streams[stream_index]->priv_data;
> +
> + ret = av_append_packet(pb, packet, pkt_size);
> + if (endframe) {
> + av_packet_move_ref(pkt, packet);
> + pkt->pos = m->pos;
> + pkt->stream_index = stream_index;
> + pkt->flags |= AV_PKT_FLAG_KEY;
> + return ret;
> + }
> + }
> +
> + m->in_block = 0;
> +
> + if (m->flags % 2 == 0)
> + avio_seek(pb, m->pos + m->size, SEEK_SET);
> + }
> +
> + return AVERROR_EOF;
> +}
> +
> +static int moflex_read_close(AVFormatContext *s)
> +{
> + for (int i = 0; i < s->nb_streams; i++) {
> + AVPacket *packet = s->streams[i]->priv_data;
> +
> + av_packet_unref(packet);
Use av_packet_free() here: This way this demuxer will be compatible with
streams whose priv_data couldn't be allocated, a situation which can
happen now with streams created when reading a packet and can happen
later when read_close is called automatically on read_header failure. It
is also more in line with the documentation which says that packets
allocated with av_packet_alloc() must be freed by av_packet_free().
> + }
> +
> + return 0;
> +}
> +
> +AVInputFormat ff_moflex_demuxer = {
> + .name = "moflex",
> + .long_name = NULL_IF_CONFIG_SMALL("MobiClip MOFLEX"),
> + .priv_data_size = sizeof(MOFLEXDemuxContext),
> + .read_probe = moflex_probe,
> + .read_header = moflex_read_header,
> + .read_packet = moflex_read_packet,
> + .read_close = moflex_read_close,
> + .extensions = "moflex",
> + .flags = AVFMT_GENERIC_INDEX,
> +};
>
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