[FFmpeg-devel] [PATCH v6 01/03] libavdevice/avfoundation.m: use AudioConvert, extend supported formats
Romain Beauxis
toots at rastageeks.org
Wed Dec 29 00:50:04 EET 2021
This is the first patch of a series of 3 that fix, cleanup and enhance the
avfoundation implementation for libavdevice.
The patches have been submitted a couple of times now and have
received very nice feedback for the last two however but they do not seem
to have been considered for inclusion thus far.
These patches come from an actual user-facing application relying on
libavdevice’s implementation of avfoundation audio input. Without them,
Avfoundation is practically unusable as it will:
* Refuse to process certain specific audio input format that are actually
returned by the OS for some users (packed PCM audio)
* Drop audio frames, resulting in corrupted audio input. This might have been
unnoticed with video frames but this makes avfoundation essentially unusable
for audio.
The patches are now being included in our production build so they are tested
and usable in production.
So, this bares the question: is avfoundation still supported and actively maintained
in libavdevice? It feels that such important bugs should have been noticed by now
and also generated a little more interest in fixing them.
Thanks for y’all feedback!
— Romain
-----
Changes:
* v2: None
* v3: None
* v4: None
* v5: Fix indentation/wrapping
* v6: None
* Implement support for AudioConverter
* Switch to AudioConverter's API to convert unsupported PCM
formats (non-interleaved, non-packed) to supported formats
* Minimize data copy.
This fixes: https://trac.ffmpeg.org/ticket/9502
API ref:
https://developer.apple.com/documentation/audiotoolbox/audio_converter_services
Signed-off-by: Romain Beauxis <toots at rastageeks.org>
---
libavdevice/avfoundation.m | 250 +++++++++++++++++++++----------------
1 file changed, 144 insertions(+), 106 deletions(-)
diff --git a/libavdevice/avfoundation.m b/libavdevice/avfoundation.m
index 0cd6e646d5..79c9207cfa 100644
--- a/libavdevice/avfoundation.m
+++ b/libavdevice/avfoundation.m
@@ -111,16 +111,10 @@
int num_video_devices;
- int audio_channels;
- int audio_bits_per_sample;
- int audio_float;
- int audio_be;
- int audio_signed_integer;
- int audio_packed;
- int audio_non_interleaved;
-
- int32_t *audio_buffer;
- int audio_buffer_size;
+ UInt32 audio_buffers;
+ UInt32 audio_channels;
+ UInt32 bytes_per_sample;
+ AudioConverterRef audio_converter;
enum AVPixelFormat pixel_format;
@@ -299,7 +293,10 @@ static void destroy_context(AVFContext* ctx)
ctx->avf_delegate = NULL;
ctx->avf_audio_delegate = NULL;
- av_freep(&ctx->audio_buffer);
+ if (ctx->audio_converter) {
+ AudioConverterDispose(ctx->audio_converter);
+ ctx->audio_converter = NULL;
+ }
pthread_mutex_destroy(&ctx->frame_lock);
@@ -673,6 +670,10 @@ static int get_audio_config(AVFormatContext *s)
AVFContext *ctx = (AVFContext*)s->priv_data;
CMFormatDescriptionRef format_desc;
AVStream* stream = avformat_new_stream(s, NULL);
+ AudioStreamBasicDescription output_format = {0};
+ int audio_bits_per_sample, audio_float, audio_be;
+ int audio_signed_integer, audio_packed, audio_non_interleaved;
+ int must_convert = 0;
if (!stream) {
return 1;
@@ -690,60 +691,95 @@ static int get_audio_config(AVFormatContext *s)
avpriv_set_pts_info(stream, 64, 1, avf_time_base);
format_desc = CMSampleBufferGetFormatDescription(ctx->current_audio_frame);
- const AudioStreamBasicDescription *basic_desc = CMAudioFormatDescriptionGetStreamBasicDescription(format_desc);
+ const AudioStreamBasicDescription *input_format = CMAudioFormatDescriptionGetStreamBasicDescription(format_desc);
- if (!basic_desc) {
+ if (!input_format) {
unlock_frames(ctx);
av_log(s, AV_LOG_ERROR, "audio format not available\n");
return 1;
}
+ if (input_format->mFormatID != kAudioFormatLinearPCM) {
+ unlock_frames(ctx);
+ av_log(s, AV_LOG_ERROR, "only PCM audio format are supported at the moment\n");
+ return 1;
+ }
+
stream->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
- stream->codecpar->sample_rate = basic_desc->mSampleRate;
- stream->codecpar->channels = basic_desc->mChannelsPerFrame;
+ stream->codecpar->sample_rate = input_format->mSampleRate;
+ stream->codecpar->channels = input_format->mChannelsPerFrame;
stream->codecpar->channel_layout = av_get_default_channel_layout(stream->codecpar->channels);
- ctx->audio_channels = basic_desc->mChannelsPerFrame;
- ctx->audio_bits_per_sample = basic_desc->mBitsPerChannel;
- ctx->audio_float = basic_desc->mFormatFlags & kAudioFormatFlagIsFloat;
- ctx->audio_be = basic_desc->mFormatFlags & kAudioFormatFlagIsBigEndian;
- ctx->audio_signed_integer = basic_desc->mFormatFlags & kAudioFormatFlagIsSignedInteger;
- ctx->audio_packed = basic_desc->mFormatFlags & kAudioFormatFlagIsPacked;
- ctx->audio_non_interleaved = basic_desc->mFormatFlags & kAudioFormatFlagIsNonInterleaved;
-
- if (basic_desc->mFormatID == kAudioFormatLinearPCM &&
- ctx->audio_float &&
- ctx->audio_bits_per_sample == 32 &&
- ctx->audio_packed) {
- stream->codecpar->codec_id = ctx->audio_be ? AV_CODEC_ID_PCM_F32BE : AV_CODEC_ID_PCM_F32LE;
- } else if (basic_desc->mFormatID == kAudioFormatLinearPCM &&
- ctx->audio_signed_integer &&
- ctx->audio_bits_per_sample == 16 &&
- ctx->audio_packed) {
- stream->codecpar->codec_id = ctx->audio_be ? AV_CODEC_ID_PCM_S16BE : AV_CODEC_ID_PCM_S16LE;
- } else if (basic_desc->mFormatID == kAudioFormatLinearPCM &&
- ctx->audio_signed_integer &&
- ctx->audio_bits_per_sample == 24 &&
- ctx->audio_packed) {
- stream->codecpar->codec_id = ctx->audio_be ? AV_CODEC_ID_PCM_S24BE : AV_CODEC_ID_PCM_S24LE;
- } else if (basic_desc->mFormatID == kAudioFormatLinearPCM &&
- ctx->audio_signed_integer &&
- ctx->audio_bits_per_sample == 32 &&
- ctx->audio_packed) {
- stream->codecpar->codec_id = ctx->audio_be ? AV_CODEC_ID_PCM_S32BE : AV_CODEC_ID_PCM_S32LE;
+ audio_bits_per_sample = input_format->mBitsPerChannel;
+ audio_float = input_format->mFormatFlags & kAudioFormatFlagIsFloat;
+ audio_be = input_format->mFormatFlags & kAudioFormatFlagIsBigEndian;
+ audio_signed_integer = input_format->mFormatFlags & kAudioFormatFlagIsSignedInteger;
+ audio_packed = input_format->mFormatFlags & kAudioFormatFlagIsPacked;
+ audio_non_interleaved = input_format->mFormatFlags & kAudioFormatFlagIsNonInterleaved;
+
+ ctx->bytes_per_sample = input_format->mBitsPerChannel >> 3;
+ ctx->audio_channels = input_format->mChannelsPerFrame;
+
+ if (audio_non_interleaved) {
+ ctx->audio_buffers = input_format->mChannelsPerFrame;
} else {
- unlock_frames(ctx);
- av_log(s, AV_LOG_ERROR, "audio format is not supported\n");
- return 1;
+ ctx->audio_buffers = 1;
+ }
+
+ if (audio_non_interleaved || !audio_packed) {
+ must_convert = 1;
+ }
+
+ output_format.mBitsPerChannel = input_format->mBitsPerChannel;
+ output_format.mChannelsPerFrame = ctx->audio_channels;
+ output_format.mFramesPerPacket = 1;
+ output_format.mBytesPerFrame = output_format.mChannelsPerFrame * ctx->bytes_per_sample;
+ output_format.mBytesPerPacket = output_format.mFramesPerPacket * output_format.mBytesPerFrame;
+ output_format.mFormatFlags = kAudioFormatFlagIsPacked | audio_be;
+ output_format.mFormatID = kAudioFormatLinearPCM;
+ output_format.mReserved = 0;
+ output_format.mSampleRate = input_format->mSampleRate;
+
+ if (audio_float &&
+ audio_bits_per_sample == 32) {
+ stream->codecpar->codec_id = audio_be ? AV_CODEC_ID_PCM_F32BE : AV_CODEC_ID_PCM_F32LE;
+ output_format.mFormatFlags |= kAudioFormatFlagIsFloat;
+ } else if (audio_float &&
+ audio_bits_per_sample == 64) {
+ stream->codecpar->codec_id = audio_be ? AV_CODEC_ID_PCM_F64BE : AV_CODEC_ID_PCM_F64LE;
+ output_format.mFormatFlags |= kAudioFormatFlagIsFloat;
+ } else if (audio_signed_integer &&
+ audio_bits_per_sample == 8) {
+ stream->codecpar->codec_id = AV_CODEC_ID_PCM_S8;
+ output_format.mFormatFlags |= kAudioFormatFlagIsSignedInteger;
+ } else if (audio_signed_integer &&
+ audio_bits_per_sample == 16) {
+ stream->codecpar->codec_id = audio_be ? AV_CODEC_ID_PCM_S16BE : AV_CODEC_ID_PCM_S16LE;
+ output_format.mFormatFlags |= kAudioFormatFlagIsSignedInteger;
+ } else if (audio_signed_integer &&
+ audio_bits_per_sample == 24) {
+ stream->codecpar->codec_id = audio_be ? AV_CODEC_ID_PCM_S24BE : AV_CODEC_ID_PCM_S24LE;
+ output_format.mFormatFlags |= kAudioFormatFlagIsSignedInteger;
+ } else if (audio_signed_integer &&
+ audio_bits_per_sample == 32) {
+ stream->codecpar->codec_id = audio_be ? AV_CODEC_ID_PCM_S32BE : AV_CODEC_ID_PCM_S32LE;
+ output_format.mFormatFlags |= kAudioFormatFlagIsSignedInteger;
+ } else if (audio_signed_integer &&
+ audio_bits_per_sample == 64) {
+ stream->codecpar->codec_id = audio_be ? AV_CODEC_ID_PCM_S64BE : AV_CODEC_ID_PCM_S64LE;
+ output_format.mFormatFlags |= kAudioFormatFlagIsSignedInteger;
+ } else {
+ stream->codecpar->codec_id = audio_be ? AV_CODEC_ID_PCM_S32BE : AV_CODEC_ID_PCM_S32LE;
+ output_format.mBitsPerChannel = 32;
+ output_format.mFormatFlags |= kAudioFormatFlagIsSignedInteger;
+ must_convert = 1;
}
- if (ctx->audio_non_interleaved) {
- CMBlockBufferRef block_buffer = CMSampleBufferGetDataBuffer(ctx->current_audio_frame);
- ctx->audio_buffer_size = CMBlockBufferGetDataLength(block_buffer);
- ctx->audio_buffer = av_malloc(ctx->audio_buffer_size);
- if (!ctx->audio_buffer) {
+ if (must_convert) {
+ OSStatus ret = AudioConverterNew(input_format, &output_format, &ctx->audio_converter);
+ if (ret != noErr) {
unlock_frames(ctx);
- av_log(s, AV_LOG_ERROR, "error allocating audio buffer\n");
+ av_log(s, AV_LOG_ERROR, "Error while allocating audio converter\n");
return 1;
}
}
@@ -1048,6 +1084,7 @@ static int copy_cvpixelbuffer(AVFormatContext *s,
static int avf_read_packet(AVFormatContext *s, AVPacket *pkt)
{
+ OSStatus ret;
AVFContext* ctx = (AVFContext*)s->priv_data;
do {
@@ -1091,7 +1128,7 @@ static int avf_read_packet(AVFormatContext *s, AVPacket *pkt)
status = copy_cvpixelbuffer(s, image_buffer, pkt);
} else {
status = 0;
- OSStatus ret = CMBlockBufferCopyDataBytes(block_buffer, 0, pkt->size, pkt->data);
+ ret = CMBlockBufferCopyDataBytes(block_buffer, 0, pkt->size, pkt->data);
if (ret != kCMBlockBufferNoErr) {
status = AVERROR(EIO);
}
@@ -1105,82 +1142,83 @@ static int avf_read_packet(AVFormatContext *s, AVPacket *pkt)
}
} else if (ctx->current_audio_frame != nil) {
CMBlockBufferRef block_buffer = CMSampleBufferGetDataBuffer(ctx->current_audio_frame);
- int block_buffer_size = CMBlockBufferGetDataLength(block_buffer);
- if (!block_buffer || !block_buffer_size) {
- unlock_frames(ctx);
- return AVERROR(EIO);
- }
+ size_t input_size = CMBlockBufferGetDataLength(block_buffer);
+ int buffer_size = input_size / ctx->audio_buffers;
+ int nb_samples = input_size / (ctx->audio_channels * ctx->bytes_per_sample);
+ int output_size = buffer_size;
- if (ctx->audio_non_interleaved && block_buffer_size > ctx->audio_buffer_size) {
+ UInt32 size = sizeof(output_size);
+ ret = AudioConverterGetProperty(ctx->audio_converter, kAudioConverterPropertyCalculateOutputBufferSize, &size, &output_size);
+ if (ret != noErr) {
unlock_frames(ctx);
- return AVERROR_BUFFER_TOO_SMALL;
+ return AVERROR(EIO);
}
- if (av_new_packet(pkt, block_buffer_size) < 0) {
+ if (av_new_packet(pkt, output_size) < 0) {
unlock_frames(ctx);
return AVERROR(EIO);
}
- CMItemCount count;
- CMSampleTimingInfo timing_info;
+ if (ctx->audio_converter) {
+ size_t input_buffer_size = offsetof(AudioBufferList, mBuffers[0]) + (sizeof(AudioBuffer) * ctx->audio_buffers);
+ AudioBufferList *input_buffer = av_malloc(input_buffer_size);
- if (CMSampleBufferGetOutputSampleTimingInfoArray(ctx->current_audio_frame, 1, &timing_info, &count) == noErr) {
- AVRational timebase_q = av_make_q(1, timing_info.presentationTimeStamp.timescale);
- pkt->pts = pkt->dts = av_rescale_q(timing_info.presentationTimeStamp.value, timebase_q, avf_time_base_q);
- }
+ input_buffer->mNumberBuffers = ctx->audio_buffers;
- pkt->stream_index = ctx->audio_stream_index;
- pkt->flags |= AV_PKT_FLAG_KEY;
+ for (int c = 0; c < ctx->audio_buffers; c++) {
+ input_buffer->mBuffers[c].mNumberChannels = 1;
- if (ctx->audio_non_interleaved) {
- int sample, c, shift, num_samples;
+ ret = CMBlockBufferGetDataPointer(block_buffer, c * buffer_size, (size_t *)&input_buffer->mBuffers[c].mDataByteSize, NULL, (void *)&input_buffer->mBuffers[c].mData);
- OSStatus ret = CMBlockBufferCopyDataBytes(block_buffer, 0, pkt->size, ctx->audio_buffer);
- if (ret != kCMBlockBufferNoErr) {
- unlock_frames(ctx);
- return AVERROR(EIO);
+ if (ret != kCMBlockBufferNoErr) {
+ av_free(input_buffer);
+ unlock_frames(ctx);
+ return AVERROR(EIO);
+ }
}
- num_samples = pkt->size / (ctx->audio_channels * (ctx->audio_bits_per_sample >> 3));
-
- // transform decoded frame into output format
- #define INTERLEAVE_OUTPUT(bps) \
- { \
- int##bps##_t **src; \
- int##bps##_t *dest; \
- src = av_malloc(ctx->audio_channels * sizeof(int##bps##_t*)); \
- if (!src) { \
- unlock_frames(ctx); \
- return AVERROR(EIO); \
- } \
- \
- for (c = 0; c < ctx->audio_channels; c++) { \
- src[c] = ((int##bps##_t*)ctx->audio_buffer) + c * num_samples; \
- } \
- dest = (int##bps##_t*)pkt->data; \
- shift = bps - ctx->audio_bits_per_sample; \
- for (sample = 0; sample < num_samples; sample++) \
- for (c = 0; c < ctx->audio_channels; c++) \
- *dest++ = src[c][sample] << shift; \
- av_freep(&src); \
- }
+ AudioBufferList output_buffer = {
+ .mNumberBuffers = 1,
+ .mBuffers[0] = {
+ .mNumberChannels = ctx->audio_channels,
+ .mDataByteSize = pkt->size,
+ .mData = pkt->data
+ }
+ };
- if (ctx->audio_bits_per_sample <= 16) {
- INTERLEAVE_OUTPUT(16)
- } else {
- INTERLEAVE_OUTPUT(32)
- }
- } else {
- OSStatus ret = CMBlockBufferCopyDataBytes(block_buffer, 0, pkt->size, pkt->data);
- if (ret != kCMBlockBufferNoErr) {
+ ret = AudioConverterConvertComplexBuffer(ctx->audio_converter, nb_samples, input_buffer, &output_buffer);
+ av_free(input_buffer);
+
+ if (ret != noErr) {
unlock_frames(ctx);
return AVERROR(EIO);
}
+
+ pkt->size = output_buffer.mBuffers[0].mDataByteSize;
+ } else {
+ ret = CMBlockBufferCopyDataBytes(block_buffer, 0, pkt->size, pkt->data);
+ if (ret != kCMBlockBufferNoErr) {
+ unlock_frames(ctx);
+ return AVERROR(EIO);
+ }
}
+ CMItemCount count;
+ CMSampleTimingInfo timing_info;
+
+ if (CMSampleBufferGetOutputSampleTimingInfoArray(ctx->current_audio_frame, 1, &timing_info, &count) == noErr) {
+ AVRational timebase_q = av_make_q(1, timing_info.presentationTimeStamp.timescale);
+ pkt->pts = pkt->dts = av_rescale_q(timing_info.presentationTimeStamp.value, timebase_q, avf_time_base_q);
+ }
+
+ pkt->stream_index = ctx->audio_stream_index;
+ pkt->flags |= AV_PKT_FLAG_KEY;
+
CFRelease(ctx->current_audio_frame);
ctx->current_audio_frame = nil;
+
+ unlock_frames(ctx);
} else {
pkt->data = NULL;
unlock_frames(ctx);
--
2.32.0 (Apple Git-132)
More information about the ffmpeg-devel
mailing list