[FFmpeg-cvslog] avformat: add amv muxer
Zane van Iperen
git at videolan.org
Mon Nov 9 07:12:34 EET 2020
ffmpeg | branch: master | Zane van Iperen <zane at zanevaniperen.com> | Mon Nov 2 15:47:32 2020 +1000| [a2fea0f4690e4f11ba093f14509643c44a485165] | committer: Zane van Iperen
avformat: add amv muxer
AMV is a hard-coded (and broken) subset of AVI. It's not worth sullying
the existing AVI muxer with its filth.
Fixes ticket #747.
Signed-off-by: Zane van Iperen <zane at zanevaniperen.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a2fea0f4690e4f11ba093f14509643c44a485165
---
MAINTAINERS | 1 +
libavformat/Makefile | 1 +
libavformat/allformats.c | 1 +
libavformat/amvenc.c | 413 +++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 416 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 7a4161e2e5..2464f82be3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -394,6 +394,7 @@ Muxers/Demuxers:
aiffdec.c Baptiste Coudurier, Matthieu Bouron
aiffenc.c Baptiste Coudurier, Matthieu Bouron
alp.c Zane van Iperen
+ amvenc.c Zane van Iperen
apm.c Zane van Iperen
apngdec.c Benoit Fouet
argo_asf.c Zane van Iperen
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 25bb8b2c69..be5a482b01 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -93,6 +93,7 @@ OBJS-$(CONFIG_AMR_DEMUXER) += amr.o
OBJS-$(CONFIG_AMR_MUXER) += amr.o rawenc.o
OBJS-$(CONFIG_AMRNB_DEMUXER) += amr.o
OBJS-$(CONFIG_AMRWB_DEMUXER) += amr.o
+OBJS-$(CONFIG_AMV_MUXER) += amvenc.o
OBJS-$(CONFIG_ANM_DEMUXER) += anm.o
OBJS-$(CONFIG_APC_DEMUXER) += apc.o
OBJS-$(CONFIG_APE_DEMUXER) += ape.o apetag.o img2.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 9b1b611a49..53e5374255 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -54,6 +54,7 @@ extern AVInputFormat ff_amr_demuxer;
extern AVOutputFormat ff_amr_muxer;
extern AVInputFormat ff_amrnb_demuxer;
extern AVInputFormat ff_amrwb_demuxer;
+extern AVOutputFormat ff_amv_muxer;
extern AVInputFormat ff_anm_demuxer;
extern AVInputFormat ff_apc_demuxer;
extern AVInputFormat ff_ape_demuxer;
diff --git a/libavformat/amvenc.c b/libavformat/amvenc.c
new file mode 100644
index 0000000000..4d4ec7a2b1
--- /dev/null
+++ b/libavformat/amvenc.c
@@ -0,0 +1,413 @@
+/*
+ * AMV muxer
+ *
+ * Copyright (C) 2020 Zane van Iperen (zane at zanevaniperen.com)
+ *
+ * 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 "riff.h"
+#include "internal.h"
+#include "avio_internal.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/avassert.h"
+
+/*
+ * Things to note:
+ * - AMV is a hard-coded (and broken) subset of AVI. It's not worth sullying the
+ * existing AVI muxer with its filth.
+ * - No separate demuxer as the existing AVI demuxer can handle these.
+ * - The sizes of certain tags are deliberately set to 0 as some players break
+ * when they're set correctly. Ditto with some header fields.
+ * - There is no index.
+ * - Players are **very** sensitive to the frame order and sizes.
+ * - Frames must be strictly interleaved as V-A, any V-V or A-A will
+ * cause crashes.
+ * - Variable video frame sizes seem to be handled fine.
+ * - Variable audio frame sizes cause crashes.
+ * - If audio is shorter than video, it's padded with silence.
+ * - If video is shorter than audio, the most recent frame is repeated.
+ */
+
+#define AMV_STREAM_COUNT 2
+#define AMV_STREAM_VIDEO 0
+#define AMV_STREAM_AUDIO 1
+#define AMV_VIDEO_STRH_SIZE 56
+#define AMV_VIDEO_STRF_SIZE 36
+#define AMV_AUDIO_STRH_SIZE 48
+#define AMV_AUDIO_STRF_SIZE 20 /* sizeof(WAVEFORMATEX) + 2 */
+
+typedef struct AMVContext
+{
+ int64_t riff_start;
+ int64_t movi_list;
+ int64_t offset_duration;
+ int last_stream;
+
+ int32_t us_per_frame; /* Microseconds per frame. */
+
+ int32_t aframe_size; /* Expected audio frame size. */
+ int32_t ablock_align; /* Expected audio block align. */
+ AVPacket apad; /* Dummy audio packet for padding. */
+ AVPacket vpad; /* Most recent video frame, for padding. */
+
+ /*
+ * Cumulative PTS values for each stream, used for the final
+ * duration calculcation.
+ */
+ int64_t lastpts[AMV_STREAM_COUNT];
+} AMVContext;
+
+/* ff_{start,end}_tag(), but sets the size to 0. */
+static int64_t amv_start_tag(AVIOContext *pb, const char *tag)
+{
+ ffio_wfourcc(pb, tag);
+ avio_wl32(pb, 0);
+ return avio_tell(pb);
+}
+
+static void amv_end_tag(AVIOContext *pb, int64_t start)
+{
+ int64_t pos;
+ av_assert0((start&1) == 0);
+
+ pos = avio_tell(pb);
+ if (pos & 1)
+ avio_w8(pb, 0);
+}
+
+static av_cold int amv_init(AVFormatContext *s)
+{
+ AMVContext *amv = s->priv_data;
+ AVStream *vst, *ast;
+ int ret;
+
+ amv->last_stream = -1;
+
+ if (s->nb_streams != AMV_STREAM_COUNT) {
+ av_log(s, AV_LOG_ERROR, "AMV files only support 2 streams\n");
+ return AVERROR(EINVAL);
+ }
+
+ vst = s->streams[AMV_STREAM_VIDEO];
+ ast = s->streams[AMV_STREAM_AUDIO];
+
+ if (vst->codecpar->codec_id != AV_CODEC_ID_AMV) {
+ av_log(s, AV_LOG_ERROR, "First AMV stream must be %s\n",
+ avcodec_get_name(AV_CODEC_ID_AMV));
+ return AVERROR(EINVAL);
+ }
+
+ if (ast->codecpar->codec_id != AV_CODEC_ID_ADPCM_IMA_AMV) {
+ av_log(s, AV_LOG_ERROR, "Second AMV stream must be %s\n",
+ avcodec_get_name(AV_CODEC_ID_ADPCM_IMA_AMV));
+ return AVERROR(EINVAL);
+ }
+
+ /* These files are broken-enough as they are. They shouldn't be streamed. */
+ if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL)) {
+ av_log(s, AV_LOG_ERROR, "Stream not seekable, unable to write output file\n");
+ return AVERROR(EINVAL);
+ }
+
+ amv->us_per_frame = av_rescale(AV_TIME_BASE, vst->time_base.num, vst->time_base.den);
+ amv->aframe_size = av_rescale(ast->codecpar->sample_rate, amv->us_per_frame, AV_TIME_BASE);
+ amv->ablock_align = 8 + (FFALIGN(amv->aframe_size, 2) / 2);
+
+ av_log(s, AV_LOG_TRACE, "us_per_frame = %d\n", amv->us_per_frame);
+ av_log(s, AV_LOG_TRACE, "aframe_size = %d\n", amv->aframe_size);
+ av_log(s, AV_LOG_TRACE, "ablock_align = %d\n", amv->ablock_align);
+
+ /*
+ * Bail if the framerate's too high. Prevents the audio frame size from
+ * getting too small. 63fps is the closest value to 60fps that divides
+ * cleanly, so cap it there.
+ */
+ if (amv->us_per_frame < 15873) {
+ av_log(s, AV_LOG_ERROR, "Refusing to mux >63fps video\n");
+ return AVERROR(EINVAL);
+ }
+
+ /*
+ * frame_size will be set if coming from the encoder.
+ * Make sure the its been configured correctly. The audio frame duration
+ * needs to match that of the video.
+ */
+ if (ast->codecpar->frame_size) {
+ AVCodecParameters *par = ast->codecpar;
+ int bad = 0;
+
+ if (par->frame_size != amv->aframe_size) {
+ av_log(s, AV_LOG_ERROR, "Invalid audio frame size. Got %d, wanted %d\n",
+ par->frame_size, amv->aframe_size);
+ bad = 1;
+ }
+
+ if (par->block_align != amv->ablock_align) {
+ av_log(s, AV_LOG_ERROR, "Invalid audio block align. Got %d, wanted %d\n",
+ par->block_align, amv->ablock_align);
+ bad = 1;
+ }
+
+ if (bad) {
+ av_log(s, AV_LOG_ERROR, "Try -block_size %d\n", amv->aframe_size);
+ return AVERROR(EINVAL);
+ }
+
+ if (ast->codecpar->sample_rate % amv->aframe_size) {
+ av_log(s, AV_LOG_ERROR, "Audio sample rate not a multiple of the frame size.\n"
+ "Please change video frame rate. Suggested rates: 10,14,15,18,21,25,30\n");
+ return AVERROR(EINVAL);
+ }
+ } else {
+ /* If remuxing from the same source, then this will match the video. */
+ int32_t aus = av_rescale(AV_TIME_BASE, ast->time_base.num, ast->time_base.den);
+ if (aus != amv->us_per_frame) {
+ av_log(s, AV_LOG_ERROR, "Cannot remux streams with a different time base\n");
+ return AVERROR(EINVAL);
+ }
+ }
+
+ /* Allocate and fill dummy packet so we can pad the audio. */
+ if ((ret = av_new_packet(&amv->apad, amv->ablock_align)) < 0)
+ return ret;
+
+ amv->apad.stream_index = AMV_STREAM_AUDIO;
+ memset(amv->apad.data, 0, amv->ablock_align);
+ AV_WL32(amv->apad.data + 4, amv->aframe_size);
+
+ av_init_packet(&amv->vpad);
+ amv->vpad.stream_index = AMV_STREAM_VIDEO;
+ amv->vpad.duration = 1;
+ return 0;
+}
+
+static void amv_deinit(AVFormatContext *s)
+{
+ AMVContext *amv = s->priv_data;
+
+ av_packet_unref(&amv->apad);
+ av_packet_unref(&amv->vpad);
+}
+
+static void amv_write_vlist(AVFormatContext *s, AVCodecParameters *par)
+{
+ int64_t tag_list, tag_str;
+
+ av_assert0(par->codec_id == AV_CODEC_ID_AMV);
+
+ tag_list = amv_start_tag(s->pb, "LIST");
+ ffio_wfourcc(s->pb, "strl");
+ tag_str = ff_start_tag(s->pb, "strh");
+ ffio_fill(s->pb, 0, AMV_VIDEO_STRH_SIZE);
+ ff_end_tag(s->pb, tag_str);
+
+ tag_str = ff_start_tag(s->pb, "strf");
+ ffio_fill(s->pb, 0, AMV_VIDEO_STRF_SIZE);
+ ff_end_tag(s->pb, tag_str);
+
+ amv_end_tag(s->pb, tag_list);
+}
+
+static void amv_write_alist(AVFormatContext *s, AVCodecParameters *par)
+{
+ uint8_t buf[AMV_AUDIO_STRF_SIZE];
+ AVIOContext *pb = s->pb;
+ int64_t tag_list, tag_str;
+
+ av_assert0(par->codec_id == AV_CODEC_ID_ADPCM_IMA_AMV);
+
+ tag_list = amv_start_tag(pb, "LIST");
+ ffio_wfourcc(pb, "strl");
+ tag_str = ff_start_tag(pb, "strh");
+ ffio_fill(s->pb, 0, AMV_AUDIO_STRH_SIZE);
+ ff_end_tag(pb, tag_str);
+
+ /* Bodge an (incorrect) WAVEFORMATEX (+2 pad bytes) */
+ tag_str = ff_start_tag(pb, "strf");
+ AV_WL16(buf + 0, 1);
+ AV_WL16(buf + 2, par->channels);
+ AV_WL32(buf + 4, par->sample_rate);
+ AV_WL32(buf + 8, par->sample_rate * par->channels * 2);
+ AV_WL16(buf + 12, 2);
+ AV_WL16(buf + 14, 16);
+ AV_WL16(buf + 16, 0);
+ AV_WL16(buf + 18, 0);
+ avio_write(pb, buf, AMV_AUDIO_STRF_SIZE);
+ ff_end_tag(pb, tag_str);
+
+ amv_end_tag(pb, tag_list);
+}
+
+static int amv_write_header(AVFormatContext *s)
+{
+ AMVContext *amv = s->priv_data;
+ AVIOContext *pb = s->pb;
+ AVStream *vst = s->streams[AMV_STREAM_VIDEO];
+ AVStream *ast = s->streams[AMV_STREAM_AUDIO];
+ uint8_t amvh[56] = {0};
+ int64_t list1;
+
+ amv->riff_start = amv_start_tag(pb, "RIFF");
+ ffio_wfourcc(pb, "AMV ");
+ list1 = amv_start_tag(pb, "LIST");
+ ffio_wfourcc(pb, "hdrl");
+
+ ffio_wfourcc(pb, "amvh");
+ avio_wl32(pb, 56);
+
+ AV_WL32(amvh + 0, amv->us_per_frame);
+ AV_WL32(amvh + 32, vst->codecpar->width);
+ AV_WL32(amvh + 36, vst->codecpar->height);
+ AV_WL32(amvh + 40, vst->time_base.den);
+ AV_WL32(amvh + 44, vst->time_base.num);
+ AV_WL32(amvh + 48, 0);
+ AV_WL32(amvh + 52, 0); /* duration, filled in later. */
+
+ avio_write(pb, amvh, sizeof(amvh));
+ amv->offset_duration = avio_tell(pb) - 4;
+
+ amv_write_vlist(s, vst->codecpar);
+ amv_write_alist(s, ast->codecpar);
+ amv_end_tag(pb, list1);
+
+ amv->movi_list = amv_start_tag(pb, "LIST");
+ ffio_wfourcc(pb, "movi");
+ return 0;
+}
+
+static int amv_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
+{
+ AMVContext *amv = s->priv_data;
+
+ if (pkt->stream_index == AMV_STREAM_VIDEO)
+ ffio_wfourcc(s->pb, "00dc");
+ else if (pkt->stream_index == AMV_STREAM_AUDIO)
+ ffio_wfourcc(s->pb, "01wb");
+ else
+ av_assert0(0);
+
+ if (pkt->stream_index == AMV_STREAM_AUDIO && pkt->size != amv->ablock_align) {
+ /* Can happen when remuxing files produced by another encoder. */
+ av_log(s, AV_LOG_WARNING, "Invalid audio packet size (%d != %d)\n",
+ pkt->size, amv->ablock_align);
+ }
+
+ avio_wl32(s->pb, pkt->size);
+ avio_write(s->pb, pkt->data, pkt->size);
+
+ amv->lastpts[pkt->stream_index] += pkt->duration;
+ amv->last_stream = pkt->stream_index;
+ return 0;
+}
+
+static int amv_pad(AVFormatContext *s, AVPacket *pkt)
+{
+ AMVContext *amv = s->priv_data;
+ int stream_index = pkt->stream_index;
+
+ if (stream_index != amv->last_stream)
+ return 0;
+
+ stream_index = (stream_index + 1) % s->nb_streams;
+ if (stream_index == AMV_STREAM_VIDEO)
+ return amv_write_packet_internal(s, &amv->vpad);
+ else if (stream_index == AMV_STREAM_AUDIO)
+ return amv_write_packet_internal(s, &amv->apad);
+ else
+ av_assert0(0);
+
+ return AVERROR(EINVAL);
+}
+
+static int amv_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+ AMVContext *amv = s->priv_data;
+ int ret;
+
+ /* Add a dummy frame if we've received two of the same index. */
+ if ((ret = amv_pad(s, pkt)) < 0)
+ return ret;
+
+ if ((ret = amv_write_packet_internal(s, pkt)) < 0)
+ return ret;
+
+ if (pkt->stream_index == AMV_STREAM_VIDEO) {
+ /* Save the last packet for padding. */
+ av_packet_unref(&amv->vpad);
+ if ((ret = av_packet_ref(&amv->vpad, pkt)) < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int amv_write_trailer(AVFormatContext *s)
+{
+ AMVContext *amv = s->priv_data;
+ AVStream *vst = s->streams[AMV_STREAM_VIDEO];
+ AVStream *ast = s->streams[AMV_STREAM_AUDIO];
+ int64_t maxpts, ret;
+ int hh, mm, ss;
+
+ /* Pad-out one last audio frame if needed. */
+ if (amv->last_stream == AMV_STREAM_VIDEO) {
+ if ((ret = amv_write_packet_internal(s, &amv->apad)) < 0)
+ return ret;
+ }
+
+ amv_end_tag(s->pb, amv->movi_list);
+ amv_end_tag(s->pb, amv->riff_start);
+
+ ffio_wfourcc(s->pb, "AMV_");
+ ffio_wfourcc(s->pb, "END_");
+
+ if ((ret = avio_seek(s->pb, amv->offset_duration, SEEK_SET)) < 0)
+ return ret;
+
+ /* Go back and write the duration. */
+ maxpts = FFMAX(
+ av_rescale_q(amv->lastpts[AMV_STREAM_VIDEO], vst->time_base, AV_TIME_BASE_Q),
+ av_rescale_q(amv->lastpts[AMV_STREAM_AUDIO], ast->time_base, AV_TIME_BASE_Q)
+ );
+
+ ss = maxpts / AV_TIME_BASE;
+ mm = ss / 60;
+ hh = mm / 60;
+ ss %= 60;
+ mm %= 60;
+
+ avio_w8(s->pb, ss);
+ avio_w8(s->pb, mm);
+ avio_wl16(s->pb, hh);
+ return 0;
+}
+
+AVOutputFormat ff_amv_muxer = {
+ .name = "amv",
+ .long_name = NULL_IF_CONFIG_SMALL("AMV"),
+ .mime_type = "video/amv",
+ .extensions = "amv",
+ .priv_data_size = sizeof(AMVContext),
+ .audio_codec = AV_CODEC_ID_ADPCM_IMA_AMV,
+ .video_codec = AV_CODEC_ID_AMV,
+ .init = amv_init,
+ .deinit = amv_deinit,
+ .write_header = amv_write_header,
+ .write_packet = amv_write_packet,
+ .write_trailer = amv_write_trailer,
+};
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