aports/testing/dsp/ffmpeg5.patch

Patch-Source: https://github.com/bmc0/dsp/commit/f3ac94b546361260349edeea5f1ee0ce7fac322a
From f3ac94b546361260349edeea5f1ee0ce7fac322a Mon Sep 17 00:00:00 2001
From: Michael Barbour <barbour.michael.0@gmail.com>
Date: Thu, 17 Feb 2022 21:50:55 -0500
Subject: [PATCH] ffmpeg.c: FFmpeg 5.0 fixes.

Turns out that I didn't read the documentation very carefully when writing
the ffmpeg_seek() code. AVStream->cur_dts was never part of the public API.

av_register_all() has been deprecated since FFmpeg 4.0 and was removed in
FFmpeg 5.0.
---
 ffmpeg.c | 97 +++++++++++++++++++++++++++++++-------------------------
 1 file changed, 53 insertions(+), 44 deletions(-)

diff --git a/ffmpeg.c b/ffmpeg.c
index 9ac5bef..42c5a66 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -1,5 +1,6 @@
 #include <stdlib.h>
 #include <stdio.h>
+#include <stdint.h>
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
 #include <libavutil/mathematics.h>
@@ -14,10 +15,11 @@ struct ffmpeg_state {
 	void (*readp_func)(char **, sample_t *, int, ssize_t, ssize_t);
 	int planar, bytes, stream_index, got_frame;
 	ssize_t frame_pos;
+	int64_t last_ts;
 };
 
 static const char codec_name[] = "ffmpeg";
-static int av_registered = 0;
+static int av_initialized = 0;
 
 /* Planar sample conversion functions */
 
@@ -81,45 +83,58 @@ static void read_buf_doublep(char **in, sample_t *out, int channels, ssize_t sta
 	}
 }
 
+static int get_new_frame(struct ffmpeg_state *state)
+{
+	AVPacket packet;
+	int r;
+	if (state->got_frame)
+		av_frame_unref(state->frame);
+	state->got_frame = 0;
+	state->frame_pos = 0;
+	retry:
+	if ((r = avcodec_receive_frame(state->cc, state->frame)) < 0) {
+		switch (r) {
+		case AVERROR_EOF:
+			return -1;
+		case AVERROR(EAGAIN):
+			skip_packet:
+			if (av_read_frame(state->container, &packet) < 0) {
+				avcodec_send_packet(state->cc, NULL);  /* send flush packet */
+				goto retry;
+			}
+			if (packet.stream_index != state->stream_index) {
+				av_packet_unref(&packet);
+				goto skip_packet;
+			}
+			state->last_ts = (packet.pts == AV_NOPTS_VALUE) ? packet.dts : packet.pts;
+			if (avcodec_send_packet(state->cc, &packet) < 0)
+				return 1;  /* FIXME: handle decoding errors more intelligently */
+			av_packet_unref(&packet);
+			break;
+		default:
+			return 1;  /* FIXME: handle decoding errors more intelligently */
+		}
+	}
+	state->got_frame = 1;
+	return 0;
+}
+
 ssize_t ffmpeg_read(struct codec *c, sample_t *buf, ssize_t frames)
 {
 	struct ffmpeg_state *state = (struct ffmpeg_state *) c->data;
-	AVPacket packet;
 	int r, done = 0;  /* set to 1 at EOF */
 	ssize_t buf_pos = 0, avail = 0;
 	if (state->got_frame)
 		avail = state->frame->nb_samples - state->frame_pos;
 	while (buf_pos < frames && !(done && avail == 0)) {
 		if (avail == 0) {
-			if (state->got_frame)
-				av_frame_unref(state->frame);
-			state->got_frame = 0;
-			state->frame_pos = 0;
-			retry:
-			if ((r = avcodec_receive_frame(state->cc, state->frame)) < 0) {
-				switch (r) {
-				case AVERROR_EOF:
-					done = 1;
-					continue;
-				case AVERROR(EAGAIN):
-					skip_packet:
-					if (av_read_frame(state->container, &packet) < 0) {
-						avcodec_send_packet(state->cc, NULL);  /* send flush packet */
-						goto retry;
-					}
-					if (packet.stream_index != state->stream_index) {
-						av_packet_unref(&packet);
-						goto skip_packet;
-					}
-					if (avcodec_send_packet(state->cc, &packet) < 0)
-						return 0;  /* FIXME: handle decoding errors more intelligently */
-					av_packet_unref(&packet);
-					break;
-				default:
-					return 0;  /* FIXME: handle decoding errors more intelligently */
-				}
+			r = get_new_frame(state);
+			if (r < 0) {
+				done = 1;
+				continue;
 			}
-			state->got_frame = 1;
+			else if (r > 0)
+				return 0;
 		}
 		if (state->got_frame) {
 			avail = (avail > frames - buf_pos) ? frames - buf_pos : avail;
@@ -145,8 +160,7 @@ ssize_t ffmpeg_write(struct codec *c, sample_t *buf, ssize_t frames)
 ssize_t ffmpeg_seek(struct codec *c, ssize_t pos)
 {
 	AVStream *st;
-	int64_t timestamp;
-	int seek_flags = 0;
+	int64_t seek_ts;
 	struct ffmpeg_state *state = (struct ffmpeg_state *) c->data;
 	if (c->frames == -1)
 		return -1;
@@ -155,16 +169,12 @@ ssize_t ffmpeg_seek(struct codec *c, ssize_t pos)
 	else if (pos >= c->frames)
 		pos = c->frames - 1;
 	st = state->container->streams[state->stream_index];
-	timestamp = av_rescale(pos, st->time_base.den, st->time_base.num) / c->fs;
-	if (timestamp < st->cur_dts)
-		seek_flags |= AVSEEK_FLAG_BACKWARD;
-	if (av_seek_frame(state->container, state->stream_index, timestamp, seek_flags) < 0)
+	seek_ts = av_rescale(pos, st->time_base.den, st->time_base.num) / c->fs;
+	if (avformat_seek_file(state->container, state->stream_index, INT64_MIN, seek_ts, INT64_MAX, 0) < 0)
 		return -1;
 	avcodec_flush_buffers(state->cc);
-	if (state->got_frame)
-		av_frame_unref(state->frame);
-	state->got_frame = 0;
-	pos = av_rescale(st->cur_dts, st->time_base.num * c->fs, st->time_base.den);
+	get_new_frame(state);
+	pos = av_rescale(state->last_ts, st->time_base.num * c->fs, st->time_base.den);
 	return pos;
 }
 
@@ -199,15 +209,14 @@ struct codec * ffmpeg_codec_init(const char *path, const char *type, const char
 	struct ffmpeg_state *state = NULL;
 	struct codec *c = NULL;
 	AVStream *st;
-	AVCodec *codec = NULL;
+	const AVCodec *codec = NULL;
 
-	if (!av_registered) {
+	if (!av_initialized) {
 		if (LOGLEVEL(LL_VERBOSE))
 			av_log_set_level(AV_LOG_VERBOSE);
 		else if (LOGLEVEL(LL_SILENT))
 			av_log_set_level(AV_LOG_QUIET);
-		av_register_all();
-		av_registered = 1;
+		av_initialized = 1;
 	}
 
 	/* open input and find stream info */