[FFmpeg-user] problem transcoding raw g729 to wav format

[Dave Horton]

Adding a bit more information to this one…..

This also seems somewhat stream-dependant, in that at times when I try to transcode two streams (one at a time) where the streams are opposite sides of the same conversation (i.e. one being the caller speaking and one being the callee), one of the streams will result in an empty file (as originally shown) and one may end up with warnings/errors in the log but yet a wav file is produced.

Here are the logs from the latter case:

ffmpeg -loglevel debug -threads 1 -y -acodec g729 -f g729 -i pipe:0 -ar 44100 -acodec pcm_s32le -f wav pipe:1

transcoder err output: [g729 @ 0x3e25da0] Before avformat_find_stream_info() pos: 0 bytes read:4096 seeks:0 nb_streams:1 
[g729 @ 0x3e25da0] All info found 
[g729 @ 0x3e25da0] After avformat_find_stream_info() pos: 10 bytes read:4096 seeks:0 frames:1
 Guessed Channel Layout for Input Stream #0.0 : mono 
Input #0, g729, from 'pipe:0': Duration: N/A, start: 0.000000, bitrate: 8 kb/s Stream #0:0, 1, 1/8000: Audio: g729, 8000 Hz, mono, s16 
Successfully opened the file. 
Parsing a group of options: output url pipe:1. 
Applying option ar (set audio sampling rate (in Hz)) with argument 44100. 
Applying option acodec (force audio codec ('copy' to copy stream)) with argument pcm_s32le. 
Applying option f (force format) with argument wav. 
Successfully parsed a group of options. 
Opening an output file: pipe:1. 
[pipe @ 0x3e2ad20] Setting default whitelist 'crypto’ 
Successfully opened the file. 
Stream mapping: Stream #0:0 -> #0:0 (g729 (native) -> pcm_s32le (native)) 
cur_dts is invalid (this is harmless if it occurs once at the start per stream) 
[g729 @ 0x3e27a00] Packet type: G.729 @ 8kbit/s detected 8 logical cores

 [graph_0_in_0_0 @ 0x3e2dfa0] Setting 'time_base' to value '1/8000’
 [graph_0_in_0_0 @ 0x3e2dfa0] Setting 'sample_rate' to value '8000’ 
[graph_0_in_0_0 @ 0x3e2dfa0] Setting 'sample_fmt' to value 's16’ 
[graph_0_in_0_0 @ 0x3e2dfa0] Setting 'channel_layout' to value '0x4’ 
[graph_0_in_0_0 @ 0x3e2dfa0] tb:1/8000 samplefmt:s16 samplerate:8000 chlayout:0x4 
[format_out_0_0 @ 0x3e2bca0] Setting 'sample_fmts' to value 's32’ 
[format_out_0_0 @ 0x3e2bca0] Setting 'sample_rates' to value '44100’ 
[format_out_0_0 @ 0x3e2bca0] auto-inserting filter 'auto_resampler_0' between the filter 'Parsed_anull_0' and the filter 'format_out_0_0' 
[AVFilterGraph @ 0x3e2cb40] query_formats: 4 queried, 6 merged, 3 already done, 0 delayed 
[auto_resampler_0 @ 0x3e40140] [SWR @ 0x3e404e0] Using fltp internally between filters 
[auto_resampler_0 @ 0x3e40140] ch:1 chl:mono fmt:s16 r:8000Hz -> ch:1 chl:mono fmt:s32 r:44100Hz 
Output #0, wav, to 'pipe:1': 
Metadata: ISFT : Lavf57.82.100 
Stream #0:0, 0, 1/44100: Audio: pcm_s32le ([1][0][0][0] / 0x0001), 44100 Hz, mono, s32, 1411 kb/s 
Metadata: encoder : Lavc57.106.101 pcm_s32le [g729 @ 0x3e27a00] Packet type: G.729 @ 8kbit/s 
[wav @ 0x3e28480] Non-monotonous DTS in output stream 0:0; previous: 0, current: -82; changing to 0. This may result in incorrect timestamps in the output file. 
[g729 @ 0x3e27a00] Packet type: G.729 @ 8kbit/s 
[wav @ 0x3e28480] Non-monotonous DTS in output stream 0:0; previous: 0, current: -77; changing to 0. This may result in incorrect timestamps in the output file. 
[g729 @ 0x3e27a00] Packet type: G.729 @ 8kbit/s [wav @ 0x3e28480] Non-monotonous DTS in output stream 0:0; previous: 0, current: -71; changing to 0. This may result in incorrect timestamps in the output file. 
[g729 @ 0x3e27a00] Packet type: G.729 @ 8kbit/s [wav @ 0x3e28480] Non-monotonous DTS in output stream 0:0; previous: 0, current: -66; changing to 0. This may result in incorrect timestamps in the output file. 
[g729 @ 0x3e27a00] Packet type: G.729 @ 8kbit/s [wav @ 0x3e28480] Non-monotonous DTS in output stream 0:0; previous: 0, current: -60; changing to 0. This may result in incorrect timestamps in the output file. 
[g729 @ 0x3e27a00] Packet type: G.729 @ 8kbit/s [wav @ 0x3e28480] Non-monotonous DTS in output stream 0:0; previous: 0, current: -55; changing to 0. This may result in incorrect timestamps in the output file. 
[g729 @ 0x3e27a00] Packet type: G.729 @ 8kbit/s [wav @ 0x3e28480] Non-monotonous DTS in output stream 0:0; previous: 0, current: -49; changing to 0. This may result in incorrect timestamps in the output file. 
[g729 @ 0x3e27a00] Packet type: G.729 @ 8kbit/s [wav @ 0x3e28480] Non-monotonous DTS in output stream 0:0; previous: 0, current: -44; changing to 0. This may result in incorrect timestamps in the output file. 
[g729 @ 0x3e27a00] Packet type: G.729 @ 8kbit/s [wav @ 0x3e28480] Non-monotonous DTS in output stream 0:0; previous: 0, current: -38; changing to 0. This may result in incorrect timestamps in the output file. 
[g729 @ 0x3e27a00] Packet type: G.729 @ 8kbit/s [wav @ 0x3e28480] Non-monotonous DTS in output stream 0:0; previous: 0, current: -33; changing to 0. This may result in incorrect timestamps in the output file.